This is a 60 Tooth aluminum sprocket for #40 chain only. It works with hub part numbers A1269 and A1292. The sprocket has a 2 ⅛” pilot and a 2 ⅞” bolt circle. It has been lightened and weighs only 14.0 oz..
This sprocket was my prototype for part #A1304. IT was used to test fit and function. It has less than 30 minutes actual run time on it.