The 304 silencer is recommended for most two-stroke applications. The slightly longer body offers reduced noise output when compared to the R-304. The brushed aluminum body, stainless steel inlet tube and end-cap give you a silencer that looks as good as it performs.Features: Longer body design helps to reduce noise output 6061 T6 brushed aluminum silencer body Stainless steel end-cap Tig and mig welded for strength and durability Double-walled mounting bracket(s) Allen head screws ensure easy repacking when needed for extended product life Made in the USA