Designed to fit with aftermarket bumpers, MagnaFlow high clearance design for off-road rock crawlers melds quality with durability. Mandrel-bent tubing and a perforated steel core boost exhaust flow and the parts are dyno proven to produce maximum power. Rock Crawler Series Stainless Cat-Back System The Rock Crawler Series Series Exhaust System delivers a high clearance design for off-road rock crawlers in need of quality, durability and performance.