DOP24440MS440 Stihl MS440 Dual Port Muffler No. 1125-140-0612. This is a high quality aftermarket dual port muffler that includes the spark arrestor screens. Replaces Stihl chainsaw MS440 part numbers 1128-140-0603, 1128 140 0603, 1125 140 0612, and 1125-140-0612.