These chrome fishtail extensions are 30" long. Outlet is 1-7/8" diameter to fit over 1-3/4" diameter inlet. Typiccally used on Harley FLH models from 1970 thru 1984, but also works on other models. If using on a 1985 or later model motorcycle, P-clamps are required (see part #3203) Sold as a set Baffles are available for these (see part #5513)