APEX'i N1 Series Universal NA Mufflers can be used in the fabrication of practically any exhaust system. The unit consists of a canister and tip, which must be welded onto custom piping. Sound levels must be controlled through piping diameter and the effective use of resonators. These N1 Series Universal NA Mufflers are available in a variety of colors: Silver, Gold, Blue, Black, Green, and Magneta NA Muffler 60mm inlet, 90mm outlet.