NWP clutch covers (also known as chain sprocket covers) are an economical replacement option for your Stihl chainsaws. This clutch cover is made of a magnesium alloy, so it is lightweight (0.45 lbs) and strong. This is the heavy duty (Wide Discharge) version, which usually comes on larger chainsaws from the west coast. The wide discharge cover is less likely to plug up with sawdust, especially when cutting with longer bars or milling with a chainsaw.