OEM Honda sprocket side countershaft spacer, This is the spacer immediately behind the front sprocket. It is the one that spins in the countershaft oil seal. excellent condition, has some discoloration from dirt being caked on it for years, please see photos, it was never sold separately from the countershaft as far as I can tell, removed from 78 XL250S, fits the following:

78, 79, 80, 81 XL250S

79, 80 XR250