This is the Blue Silicone Pipe Coupler for the T-Maxx 2.5 This goes between the tuned pipe and the header FEATURES: Blue silicone construction For use with pipes #5152 and #4452 INCLUDES: One pipe coupler REQUIRES: Installing on the vehicle with wire ties (can use ASCC3720) SPECS: Length: 21mm Diameter: 11.5mm ID & 17.5mm OD (small end) 15.8mm ID & 21.5mm OD (large end) tjt 020503 ir/jxs