SP mufflers FD RX-7 dumpy tip catback is a free flowing 3.5" mandrel bent design for direct bolt on use with the 3.5" SMB exhaust system. It is also available in a bolt on option to suit a factory exhaust with a 3" flange (steps up to 3.5" pipe after). The SP mufflers are the ultimate performance muffler providing maximum unrestricted flow with the best sound dampening properties. 100% Aussie made handcrafted in-house full tig welded 304ss body construction pressed end cap over body dimple formed inlets/outlets for maximum strength flared inlets/outlets for pipe to slip inside for easy fitment pulse welded outlets to make welding a breeze stainless steel wrapped perf high temp fibreglass matt packing mandrel bent perforated tube for maximum flow PLEASE NOTE: If a system is out of stock please allow up to 2 weeks lead time for production.