Yes, on every Monster Clutch product except for our billet twins/triples. The reasoning behind this is these units have very, very tight tolerance setups. Because of this these things can be easily overextended and severely damaged. Most of the warranty issues we have with the billet units is from improperly adjusted aftermarket masters. If you're using these setups make absolutely sure they are adjusted every time you install a new clutch, and that adjustment is checked on a regular basis - it's very easy to damage any clutch that is made with an aftermarket master cylinder assembly - not only is this the responsibility of the end user/installer, any damages caused by this are not covered under our warranty.