This is the 10 cc .60 Quiet Tuned Pipe from Mac"s Products. FEATURES: Constructed of aluminum with polished natural finish For RC airplane applications using 10 cc (.60 cu in) engines Quieter than a muffled tuned pipe, this design has a chamber with baffles that tune the system and quiet the exhaust INCLUDES: 10 cc (.60cu in) Quiet Tuned Pipe REQUIRES: Header depending on selected engine SPECS: Length: 18.5" (470mm) Diameter: 1.6" (41.3mm) jxs 12/14/11 ir/jxs