This is a brand new rear brake drum and sprocketwith 8 hole bolt on hub.
Part # 37-1276, W1276
Sprocket teeth: 43
Chain size: 530
Chain Pitch: 5/8″ X 3/8″
Fits: Triumph pre-unit and unit T120 with bolt on hub from 1959-66
Triumph T100 with bolt on hub from 1960-67