I recently replaced some calipers from Autozone that came with a lifetime warranty.the original calipers were from Cardone.The new ones are from Femco.The parts numbers have changed on some of the calipers,off by one digit,example 424 is now 425 and so on.Autozones policy is for you to pay in full plus core charge,then they order the part.When you return the core you get a full refund.Since the new caliper numbers were off by one digit it did not show up on their computer as under lifetime warranty.They tried to tell me that the calipers I NOW bought are lifetime.I explained to them that their computer show I purchased 4 calipers 4 years ago amd now want new replacements for free,I want a complete refund.Someone finally figured it out and I got my money.But beware! If you have a lifetime warranty on any of their products and it replaced for free,make sure that the part number they order is the same as the one they have on file with your name and phone number.And if the old part number is discontinued that they make a note that the new number will replace your old item under warranty.If not get ready for a big headache.Took them 40 minutes to give me a complete refund. Beware!