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.

Shock absorber for overrun device/brake AL-KO 161S (old type) for 1600kg trailer

- For the coupling unit:

AL-KO 7/13 pin plug holder - universal size

2,49 €1070 PTS
- Model:
- Intended for::

AL-KO 2.8VB1 overrun device with AK351 hitch for 3500kg trailer with square drawbar

- Drawbar profile:
- Drawbar:
- GVW:
- Nose load:

KNOTT overrun absorber for KF7,5 750 kg

- For the coupling unit:

WINTERHOFF WW8-E ball hitch for 800kg trailer with 50mm square drawbar

13,99 €6012 PTS

WINTERHOFF WW8-G ball hitch for 800kg trailer with 60mm square drawbar

14,49 €6227 PTS

WINTERHOFF WW8-Y ball hitch for 800kg trailer with V-type drawbar

16,99 €7301 PTS

WINTERHOFF WW8-D40 ball hitch for 800kg trailer with 40mm square drawbar

14,99 €6442 PTS

AL-KO AK7 ball hitch for 750kg trailer with 60mm square drawbar

15,79 €6785 PTS

STEELPRESS ZSK-0750H ball hitch for 750kg trailer with 50mm square drawbar

12,89 €5539 PTS

WINTERHOFF WW8-A ball hitch for 800kg trailer with 50mm tubular drawbar

15,39 €6613 PTS

Bellow for overrun device AL-KO 161S/251S/251G FI50

9,49 €4078 PTS

AL-KO 251S overrun device with AK270 hitch for 2700 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

AL-KO 90S/3 overrun device with AK161 hitch for 1000 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

KNOTT KF27B overrun device with K27A hitch for 2700 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

KNOTT K7.5-L ball hitch for 750kg trailer with 60mm square drawbar

21,29 €9149 PTS

KNOTT KQ14-A ball hitch for 1400kg trailer with 50mm square drawbar

30,99 €13317 PTS

KNOTT K27-A ball hitch for a 2700kg trailer with a 50mm pipe drawbar, cast iron

57,89 €24876 PTS

WINTERHOFF WW8-C ball hitch for 800kg trailer with 70mm tubular drawbar

16,29 €7000 PTS

WINTERHOFF WW8-B ball hitch for 800kg trailer with 60mm tubular drawbar

16,49 €7086 PTS

WINTERHOFF WW8-H ball hitch for 800kg trailer with 70mm square drawbar

16,99 €7301 PTS

Plug holder cover WINTERHOFF W1707 universal 7-PIN and 13-PIN for trailer

1,99 €855 PTS

AL-KO AK301 ball hitch for 3000kg trailer with 50mm pipe drawbar, cast iron

89,79 €38585 PTS

Rubber bellows - KNOTT KF7,5-KF30 protective rubber

9,99 €4293 PTS

Rubber bellows - KNOTT KF27-KF35 safety rubber

9,99 €4293 PTS

Shock absorber for overrun device AL-KO 251S 2700 kg - new model

- For the coupling unit:
- GVW:

KNOTT K14-A ball hitch for 1400kg trailer with 50mm tubular drawbar

31,59 €13575 PTS

AL-KO 251S overrun device with AKS3004 hitch for 2700 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

AL-KO 161S overrun device with AK161 hitch for 1600kg trailer with square drawbar

- Drawbar profile:
- GVW:
- Nose load:

AL-KO 161S overrun device with AK161 hitch for 1600 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

AL-KO 251G overrun device with AK301 hitch for 3000 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

AL-KO 251S overrun device with AK270 hitch for 2600kg trailer with square drawbar

- Drawbar profile:
- Drawbar:
- GVW:
- Nose load:

AL-KO 2.8VB1 overrun device with AK351 hitch for 3500 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

AL-KO AK351 ball hitch for 3500kg trailer with 60mm pipe drawbar, cast iron

153,69 €66044 PTS

KNOTT KF13E overrun device with KK14B hitch for 1400 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

KNOTT KF20A overrun device with K20B hitch for 2000 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

KNOTT KF17A overrun device with K20B hitch for 1700 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

KNOTT KFG30A overrun device with K35A hitch for 3000 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

KNOTT KFG35D overrun device with K35C hitch for 3500 kg trailer with V-type drawbar

- Drawbar profile:
- GVW:
- Nose load:

AL-KO AK270 ball hitch for 2700kg trailer with 50mm tubular drawbar

73,99 €31795 PTS

Shock absorber for trailers AL-KO 101VB/90S

- For the coupling unit:

AL-KO 60S/2 overrun device with AK161 hitch for 750kg trailer with V-shaped drawbar

- Drawbar profile:
- GVW:
- Nose load:

AL-KO 161S overrun device with AK161 hitch for 1600kg trailer with square drawbar

- Drawbar profile:
- Drawbar:
- GVW:
- Nose load:

WINTERHOFF WW13-N ball hitch for 1500kg trailer with 45mm tubular drawbar

40,99 €17614 PTS

WINTERHOFF WW150-RB ball hitch for 1500kg trailer with 50mm tubular drawbar


Support bracket for overrun device AL-KO 150 mm

8,99 €3863 PTS
- Material:
- Height:

AL-KO AKS3004 ball hitch with stabilizer for 3000kg trailer with 50mm tubular drawbar


AL-KO AK161 ball hitch for 1600kg trailer with 50mm tubular drawbar

68,99 €29646 PTS

KNOTT KF27B overrun device with K27A hitch for a 2700 kg trailer with a V-shaped drawbar and a support wheel bracket

- Drawbar profile:
- GVW:
- Nose load:

Trailer bellow - rubber protection for KNOTT overrun device KFG35

17,99 €7731 PTS

STEELPRESS ZSK-0750J ball hitch for 750kg trailer with 70mm square drawbar

23,69 €10180 PTS

STEELPRESS ZSK-0750C ball hitch for 750kg trailer with 50mm tubular drawbar

21,99 €9450 PTS

Overrun shock absorber 251S 2600 kg - old model

- For the coupling unit:
- GVW:

Trailer overrun damper 161S 1600 kg - new model

- For the coupling unit:

Overrun brake damper 251G 3000 kg

- For the coupling unit:

AL-KO overrun damper 2.8 VB/1 3500 kg

- For the coupling unit:
- 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!