The ALM Manufacturing Replacement Chainsaw Chains to fit a wide range of chainsaw makes and models.The ALMCH066 Chainsaw Chain has a 3/8 inch Low profile (L/P), 0.043in guidebar slot 0.325 mm and Low profile (L/P) 1.1 mm guidebar slot.This chain is made to fit the Ryobi range and suit saws with a 40cm bar and chain with 66 drive links including:PCN-3840, PCN-4040.