Coupling unit & Coupling head
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.

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!

Coupling head for trailers Winterhoff WW 8-E GVW 800 kg

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KNOTT overrun damper KF9 500-1000 kg

137,53 €59598 PTS
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Ball coupling for trailers WW 8-Y Winterhoff

17,00 €7367 PTS
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Coupling head for trailers Winterhoff WW 8 - A DMC 800 kg

19,99 €8662 PTS
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Overrun device for trailers AL-KO 251S 2700kg

290,00 €125669 PTS
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Coupling unit for trailers - KNOTT KF27 2700kg

281,99 €122198 PTS
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Coupling head for trailers Knott KQ14A 50 mm 1400 kg

34,99 €15163 PTS
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- Diameter of mounting holes:
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Coupling head for trailers Steelpress ZSK 750 H

20,99 €9096 PTS

Coupling head for trailers Knott K 7,5-D 60 mm 750 kg

30,49 €13213 PTS
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Coupling head for trailers Winterhoff WW 8 - GVW 800 kg

40,99 €17763 PTS
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Coupling head Winterhoff WW 8-D40 800 kg 40x40 mm

28,99 €12563 PTS
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Bellow for overrun device AL-KO 161S/251S/251G FI50

9,86 €4273 PTS
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Coupling unit for trailers AL-KO 1000 kg V 90S/3 AK 160

307,38 €133199 PTS
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AL-KO coupling unit for trailers 1600kg V 161S AK161

269,00 €116568 PTS
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Coupling for trailers AL-KO 3000kg V 251G AK301

1 784,99 €773508 PTS
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Coupling head for trailers AL-KO AK7 750 kg 60 mm

20,90 €9057 PTS
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Coupling unit KNOTT KF20A 1100-2000 kg.

355,15 €153899 PTS
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Coupling head KF27A M14 2700 kg pipe 50 mm

68,30 €29599 PTS

Coupling head AL-KO AK270 2700 kg ∅ 50 mm

80,30 €34799 PTS

Coupling head Winterhoff WW 13-N 1500 kg

34,15 €14799 PTS
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Coupling head Winterhoff WW 8-C 800 kg

78,99 €34230 PTS
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Zaczep kulowy Winterhoff WW 8-B 800 kg 60 mm

16,15 €6999 PTS
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Coupling head Winterhoff WW 8-H 800 kg 70x70 mm

14,99 €6496 PTS
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Coupling head WW 150-VG 1500 kg 70x70 mm Winterhoff

37,99 €16463 PTS
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Coupling head Winterhoff WW 150-VF 1500 kg 60x60 mm

36,99 €16029 PTS
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- For drawbar type::

Safety rubber bellow AL-KO 30S/60S/90S FI35

8,08 €3500 PTS
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Cast-iron ball coupling AK301 3000kg fi 50 mm

72,99 €31629 PTS

Rubber bellows - KNOTT KF7,5-KF30 protective rubber


Rubber bellows - KNOTT KF27-KF35 safety rubber


Trailer bellow - rubber protection for KNOTT overrun device KFG35

19,99 €8662 PTS

Coupling head for trailers Steelpress ZSK 750 J 70x70 mm

22,61 €9799 PTS
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- Material:
- Reference:
- Type of drawbar:
- Drawbar width:

Trailer coupling hitch 750 C for pipes with a 50 mm diameter

21,23 €9199 PTS

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

68,77 €29799 PTS
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Universal KNOTT overrun device cover

19,84 €8599 PTS
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Support wheel holder console AL-KO 161S, 251S, 251G

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Ball hitch for trailer Knott K14A fi 50 mm N-3

27,08 €11735 PTS
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Cover for trailer overrun device

12,99 €5629 PTS
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Coupling unit for trailers AL-KO 251S 2700kg + AKS3004

522,60 €226463 PTS
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Coupling unit for trailers AL-KO 1600kg KW100 161S AK160

461,30 €199900 PTS
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- GVW:
- Coupling type:

Coupling unit for trailers AL-KO 2600kg KW100 251S AK270

1 784,99 €773508 PTS
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Coupling unit for trailers AL-KO 3500kg KW120 2,8VB1 AK351

834,22 €361499 PTS
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- GVW:

Coupling unit for trailers AL-KO 3500kg V 2,8VB1 AK351

686,76 €297599 PTS
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- GVW:

Coupling head AL-KO AK351 3500kg for 251S

120,99 €52430 PTS
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- Type of drawbar:
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Coupling unit for trailers - KNOTT KF13 1400kg

269,00 €116568 PTS
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Coupling unit for trailers - KNOTT KF17 1700kg

1 399,99 €606672 PTS
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KNOTT KFG30 3000 kg coupling unit for trailers

494,53 €214299 PTS
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Coupling unit for trailers KNOTT KFG35D 3500kg

800,75 €346999 PTS
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AL-KO DIN drawbar eye DIN 2,8VB 351VB ⌀ 60

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

84,23 €36499 PTS
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Overrun device AL-KO 60S/2 750kg

304,84 €132099 PTS
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Coupling unit for trailer AL-KO 1600kg KW100 161S AK160

374,30 €162199 PTS
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Coupling head Winterhoff WW 150-RB 1500 kg

38,77 €16799 PTS
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Overrun device bellow AL-KO 2.8VB FI60

63,99 €27729 PTS
- Reference:

AL-KO friction pads AKS 1300

43,30 €18764 PTS

Support bracket for overrun device AL-KO 150 mm

6,66 €2888 PTS
- Reference:
- Material:
- Frame height needed:

Stabiliser coupling AL-KO AKS 3004 - up to 3000 kg

492,99 €213632 PTS

AL-KO coupling ball AK 161 1600 kg with Soft Dock

64,99 €28163 PTS
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- GVW:
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- Pipe diameter:

Overrun shock absorber 251S 2600 kg - old model

89,77 €38899 PTS
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123,21 €53392 PTS
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- Total permissible trailer weight:

Trailer overrun damper 161S 1600 kg - new model

100,80 €43681 PTS
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- Total permissible trailer weight:
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