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. Smooth, rolled end shape adds a megaphone enhancement to the sound. Spiraled louvered core exits in a trumpet-bell shape that allows the V-twin sound track to flow at full song. Sold in pairs. 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: The constant velocity cores are designed specifically for the Milwaukee Eight engine platform, to provide the best sound and performance.