Coupling heads and Overrun devices
Coupling heads and coupling units, sometimes also called overrun devices are all vital accessories when it commes to attaching the trailer onto your vehicle in a safe manner. At our online store, you will find plenty of coupling heads and coupling units, which have been produced by renowned manufacturers such as AL-KO, KNOTT, WINTERHOFF and STEELPRESS. The accessories in question boast a GVW values ranging between 700 and 3500 and are available at very affordable prices. If you want to travel risk-free with your trailer, simply get your hands on a coupling unit today and save yourself from all the hassle.

AL-KO 7/13 pin plug holder - universal size
Product available in very large quantity- Model:
- Intended for::

WINTERHOFF WW8-E ball hitch for 800kg trailer with 50mm square drawbar
Product available in very large quantity
WINTERHOFF WW8-Y ball hitch for 800kg trailer with V-type drawbar
Product available in very large quantity
AL-KO AK7 ball hitch for 750kg trailer with 60mm square drawbar
Product available in very large quantity
STEELPRESS ZSK-0750H ball hitch for 750kg trailer with 50mm square drawbar
Product available in very large quantity
KNOTT K7.5-L ball hitch for 750kg trailer with 60mm square drawbar
Product available in very large quantity
KNOTT K27-A ball hitch for a 2700kg trailer with a 50mm pipe drawbar, cast iron
Product available in very large quantity
AL-KO 251S overrun device with AK270 hitch for 2700 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

WINTERHOFF WW8-H ball hitch for 800kg trailer with 70mm square drawbar
Product available in very large quantity
Bellow for overrun device AL-KO 161S/251S/251G FI50
Product available in very large quantity
WINTERHOFF WW8-C ball hitch for 800kg trailer with 70mm tubular drawbar
Product available in very large quantity
WINTERHOFF WW8-B ball hitch for 800kg trailer with 60mm tubular drawbar
Product available in very large quantity
KNOTT KF27B overrun device with K27A hitch for 2700 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

KNOTT KQ14-A ball hitch for 1400kg trailer with 50mm square drawbar
Product available in very large quantity
Plug holder cover WINTERHOFF W1707 universal 7-PIN and 13-PIN for trailer
Product available in very large quantity
Safety rubber bellow AL-KO 30S/60S/90S FI35
Product available in very large quantity
Rubber bellows - KNOTT KF27-KF35 safety rubber
Product available in very large quantity
AL-KO 161S overrun device with AK161 hitch for 1600 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

Shock absorber for overrun device AL-KO 251S 2700 kg - new model
Product available in very large quantity- For the coupling unit:
- GVW:

KNOTT K14-A ball hitch for 1400kg trailer with 50mm tubular drawbar
Product available in very large quantity
AL-KO Soft-dock
Product available in very large quantity
Universal KNOTT overrun device cover
Product available in very large quantity
KNOTT KF27B overrun device with K27A hitch for a 2700 kg trailer with a V-shaped drawbar and a support wheel bracket
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

Trailer bellow - rubber protection for KNOTT overrun device KFG35
Product available in very large quantity
KNOTT KK14-B ball hitch for 1400kg trailer with 45mm tubular drawbar
Product available in very large quantity
AL-KO 90S/3 overrun device with AK161 hitch for 1000 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

WINTERHOFF WW8-A ball hitch for 800kg trailer with 50mm tubular drawbar
Product available in very large quantity
AL-KO AK301 ball hitch for 3000kg trailer with 50mm pipe drawbar, cast iron
Product available in very large quantity
Rubber bellows - KNOTT KF7,5-KF30 protective rubber
Product available in very large quantity
STEELPRESS ZSK-0750K ball hitch for 750kg trailer with V-shaped drawbar
Product available in very large quantity
KNOTT KQ14-B ball hitch for 1400kg trailer with 60mm square drawbar
Product available in very large quantity
AL-KO 2.8VB1 overrun device with AK351 hitch for 3500 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

AL-KO AKS3004 ball hitch with stabilizer for 3000kg trailer with 50mm tubular drawbar
Product available in small quantity
STEELPRESS ZSK-0750C ball hitch for 750kg trailer with 50mm tubular drawbar
Product available in very large quantity
KNOTT KF20A overrun device with K20B hitch for 2000 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

Overrun coupling damper KNOTT KF27A 1600-2700 kg
Product available in very large quantity- For the coupling unit:

AL-KO 251G overrun device with AK301 hitch for 3000 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

KNOTT KF13E overrun device with KK14B hitch for 1400 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

AL-KO AK270 ball hitch for 2700kg trailer with 50mm tubular drawbar
Product available in very large quantity
Support bracket for overrun device AL-KO 150 mm
Product available in very large quantity- Material:
- Height:

AL-KO 60S/2 overrun device with AK161 hitch for 750kg trailer with V-shaped drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

KNOTT KF17A overrun device with K20B hitch for 1700 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

AL-KO handbrake lever for overrun devices 161S 251S
Product available in very large quantity
Overrun device bellow AL-KO 2.8VB FI60
Product available in very large quantity
Cover for trailer overrun device
Product available in very large quantity
AL-KO 251S overrun device with AKS3004 hitch for 2700 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

AL-KO 161S overrun device with AK161 hitch for 1600kg trailer with square drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

KNOTT overrun damper for KF27B 2700 kg
Product available in very large quantity- For the coupling unit:

AL-KO AK351 ball hitch for 3500kg trailer with 60mm pipe drawbar, cast iron
Product available in very large quantity
STEELPRESS ZSK-0750J ball hitch for 750kg trailer with 70mm square drawbar
Product available in very large quantity
KNOTT KFG35D overrun device with K35C hitch for 3500 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

AL-KO friction pads AKS 1300
Product available in very large quantity
Hitch damper for KNOTT KFG30 2700-3500 kg
Product available in very large quantity- For the coupling unit:

Trailer overrun damper 161S 1600 kg - new model
Product available in very large quantity- For the coupling unit:

Shock absorber for AL-KO 2.8 VB1 overrun device/brake for 3500kg trailer
Product available in very large quantity- For the coupling unit:

AL-KO 251S device/overrun brake shock absorber (new type) for a 2700kg trailer
Product available in very large quantity- For the coupling unit:
- GVW:

Tie rod for overrun device model KF13, KF17, KF20 by KNOTT
Product available in very large quantity
Front and rear friction pads AL-KO AKS 3004/3504
Product available in very large quantity
KNOTT KFG30A overrun device with K35A hitch for 3000 kg trailer with V-type drawbar
Product available in very large quantity- Drawbar profile:
- GVW:
- Nose load:

AL-KO DIN drawbar eye DIN 2,8VB 351VB ⌀ 60
Product available in very large quantity- 1
- 2
Coupling heads
Coupling heads are used to attach the trailer onto a vehicle. There are many different types of coupling heads - coupling heads for V-shaped drawbars, coupling heads for T-shaped drawbars, coupling heads for pipe-shaped drawbars etc. The main point of difference between them however, is their maximum permissible GVW value, maximum load capacity of the coupling hook and last but not least, their spacing between mounting holes, which can all vary from model to model. In the case of coupling heads available in our online store, all the information that you need for individual coupling models can be found on the product's page.Coupling heads are equipped with a wear indicator, which helps to assess when the accessory in questions needs replacing. Another helpful source of information about the coupling head is the coupling correctness indicator, with the aid of which trailer users assess whether or not the trailer has been correctly connected onto a vehicle.
Trailer coupling units
Trailer coupling units also known as overrun devices are trailer accessories which are made up of not only a braking system but also of a coupling head and a steel casing, which connects the device together. It is possible to replace individual coupling unit parts rather than then whole set. It is also possible to equip the unit with shock absorbers.Coupling units for heavy-duty braked trailers with a GVW of 750kg or more are mounted onto drawbars of regular car trailers and tow trucks. There is no need to assemble a coupling unit onto a light-duty trailer, as it is required neither by law nor by sheer laws of physics, which would otherwise demand for a heavy-duty trailer to be equipped with such an accessory. Using a coupling unit will therefore increase safety levels when your trailer is in drive mode and will thus significantly decrease the force exerted on your car's brake system.
Car trailer coupling heads and coupling units
The more a car trailer coupling unit is used, the more likely it is that it is going to fall victim of natural wear and tear. Before you head off on a long trip, it is worth checking the wear indicator of the coupling unit and the coupling head.Coupling units are the only trailer element apart from the brake cord which connect the trailer with the towing vehicle. Assemblying the trailer coupling unit correctly is the first step which needs to be taken in order to reassure oneself of a safe drive. Here, at Unitrailer, we care about high quality products. It is for this reason that we sell only AL-KO, KNOTT, WINTERHOFF and STEELPRESS coupling units, as they offer the highest possible quality on the market. Choose the right coupling unit today and take care of your brake system the right way!








