I received the certificates for my "liftime of tires", which they figure as 4 sets. The certificates are such that I can use them at any time. I am picking up 3 sets (12 tires) to mount on my pickup, my wifes car, and my sons car (my name is on all the titles/registrations). My son works at the local tire shop and will mount them all for cost. With disposal fees, mounting. balancing, stem, etc, I should come out at about $25 for each vehicle. Not too shabby. My sons car is almost running on steal belts and he really needs these! It is nicew for my wife and I as both our rigs are getting there and we really didn't like to go in to winter without some deep tread.