Tecomec Chainsaw high quality T-Wrench 3/4" (19mm) for spark plugs and 9/16" (14mm) for bar nuts. 

This wrench works on chain saw models like the Poulan models 200, 300, 400, 405, 655, 3400, 3700

This wrench works on chain saw models like the Partner models P41, P50, P51, P60

The barrel length is 3-1/16" and the shaft length is 5-7/8"