Genuine Mini Spares product. Spacer fits up against the primary gear on the crankshaft and held on by the "C" washer
22A319 - both these parts wear as well as the gear. Now made 2 thou oversize to help corect wear issues.
Only fits cranks from 1962 on with 1.5" tail width-NOT the earlier 1.3/8" tail size. 0.164" plus or minus one thou.
The original size thickness is
88G549GENUINE