BLOX Racing 15 18 Subaru WRX 15 17 Subaru WRX STI Muffler Delete Kit BLOX Racing 15 18 Subaru WRX 15 17 Subaru WRX STI Muffler Delete Kit 2015 2021 Subaru WRX STi Muffler Delete Quad Burnt Tips Cat Back Exhau Remark Axleback Muffler Delete Set Subaru WRX STI 2015 2021 (Stealth. BLOX Racing's all black and standard version muffler delete kits are made from T304 stainless steel and TIG welded for durability and reliability against cracks and leaks. Each features OEM location hangers and includes new gaskets and hardware. BLOX Racing Muffler Delete Kits replace the OEM mufflers and greatly reduce the bulk and weight associated with them. BLOX Racing deletes are dual exit, quad tip designs and provide the classic Boxer rumble with a more aggressive and throaty tone. Vehicle Applications 2015 2021 Subaru WRX 2015 2021 Subaru STi (non SPT) T304 Muffler Delete Specs 2. 5 OD piping 3. 5" OD tips T304 stainless steel Mandrel bent tubing; TIG welded Available in matte black or standard stainless steel finish Features & Benefits Dual muffler delete design, quad tips Single wall construction Direct bolt on Includes new hardware and gaskets Replaces heavy and bulky OEM mufflers Aggressive look Throaty exhaust notes and tones Notes Bolts to 2 hole exhaust flange Will not work with aftermarket exhaust system Does not fit SPT exhaust