Genuine AL-KO friction pad shim washer kit for AKS 2004 and AKS 3004 caravan stabiliser couplings. These precision shim washers are used with the side friction pads to achieve the correct fit and positioning where shims were originally installed.

The pack contains 5 × 0.3mm and 5 × 0.5mm shim washers, allowing the required thickness to be selected when servicing or replacing the stabiliser's side friction pads. AL-KO Store UK

Please note: these are friction-pad adjustment shims, rather than washers specifically for the hitch lock. I would therefore leave “Hitch Locks” out of your title, as AL-KO's own description specifies them for the AKS 2004/3004 side friction pads.