This product is compatible with the following models:
BMW R 1200 GS 
BMW R 1200 GS Adventure [2005-2009]
MATERIAL: SUS 304 Grade Polished Stainless Steel
INNER DIAMETER (DOWNPIPE END): 54mm (2 1/8")
OUTER DIAMETER (SILENCER END): 51mm (2")
California Warning: The California Air Resources Board (“CARB”) does not permit the use of aftermarket exhaust systems that remove or alter OEM emission control devices unless certified by CARB, other than for racing vehicles on closed courses. Due to California law we are required to have all customers in California sign an acknowledgment form.