The Poulan 545139903 Chain Brake Assembly is a safety component designed to stop the chainsaw chain quickly in the event of kickback or sudden movement. This assembly works by engaging a braking mechanism that halts the chain’s motion when triggered, helping to reduce the risk of injury during operation. Positioned at the front of the saw, it also functions as a hand guard for added u... https://www.wholetoolbox.com/poulan-545139903-chain-brake-assembly