installed on my '70 xlh with drags, comes with a lock washers, but i used lock nuts for peace of mind. was too quiet for me, didn't sound like a harley. just cut 4" off, made all the difference, and was able to pass inspection. I like it that they're long enough to be able to "tune"(cut) them to a specific need. priced right and shipping was fast as always. lots of free stickers and stuff in the box sweetened the deal even more.I would definately buy them again.