Holden | Ford | Parallel | 2t Al-ko | 2t Dexter | Simplicity Dust Caps
Caps for caravans and trailers are a pressed metal fit or compressed fit as opposed to a machine fit (Bearing Buddy).

Bearing failure causes the hub bearing surface to scour on the axle. As a result, the dust cap journal becomes oversized and damaged.

Pressed metal caps are slightly larger than the hub. The circumference is squeezed during insertion. The squeezing or compression of the circumference holds the cap into place.

Couplemate have chosen a galvanised grease cap to help stop the effects of corrosion that will occur over time.

Finally, another term for a galvanised cap is grease cap. This term is misleading as it indicated grease is held in the cap. Whilst it is true, grease caps can be filled with excess grease, the more common term is dust cap.