A wonderful addition to your vintage , these brass clutch nuts replace your stock clutch pressure plate nuts (OEM # 57-2526) on your Triumph or BSA motorcycle. Stock clutch pressure plate nuts are slotted, and as you adjust them the clutch hub center studs stand proud of the nuts, necessitating a slotted tool to keep adjusting further. These custom clutch nuts are machined to use an allen tool, which is included, that allows you to quickly and evenly adjust your pressure plate. The center of the allen tool is relieved, allowing clearance for the clutch center studs as they protrude. Don't fight with your clutch spring nuts anymore, this updated style is easier to install and remove. This set of 4 brass nuts and installation / removal tool is suitable for all unit Triumph 350, 500, 650 and 750 c.c. motorcycles, as well as all BSA A50 500 and A65 650 c.c. twins from 1962 - 1972. Replaces OEM # 57-2526, 42-3199, 04-0389, 68-3246, 57-0427