Genuine Efco Chainsaw Clutch Drum & Sprocket 50050136A 

Suitable for the following Chainsaws:

136 | 137 | 140 | 141s | MT3700 | MT371 | MT3710 | MT4000 | MT4100s | MT411 | MT4110 | MT451 | MT4510

(3/8″ Low Profile Chain)