This is a Penske shock that was off a 2006 R1. I sent it to Roger at ON Road Off Road and had him completely rebuild the unit. All seals and bump stops replaced as well as valve stacks tweaked to work on our tracks and roads. This shock is just broken in with one track day on it and a handful of street miles. I had the body lengthened a little to work with the FZ1. It will still mount up to a R1 and is adjustable so it can be shorted as needed to fit the bike and rider. May work on other bikes, that is up to you to find out. Sprung for me @ 185#s. $800.00 Thanks.