Cobra Neighbor Haters Slip-On Muffler649729698 Product Description 4" round muffler body Features a 4" billet aluminum black outer tip with distinctive machined dual grooves Short body reaches the rear axle Also features 2 1 4" louvered cores to achieve their great sound and performance The core design produces good power on the stock 2 into 1 Softail head pipe, and will create even more performance when the rider decides to build more power with either a larger engine or standard