Neighbor Haters Slip-On Exhaust. The new Neighbor Haters by Cobra are not for the faint of heart. These are an aggressive slip-on muffler, for those who think loud just isn't good enough. For riders who think that too loud is just about right. Sold as a set. Limited lifetime warranty. Made in the U.S.A. Note: NOT legal for sale or use in California on and pollution-controlled motor vehicles. Detailed Specifications: 4" bodies bell out to 4-1/2" at the rear, which features a smooth, rolled end. Smooth, rolled end shape adds a megaphone enhancement to the sound. New Raven black is slightly darker than the standard black finish.