Got home and checked old cheeseblocks manufacture date 2016 in good condition they don't expire do they.i only replaced all mine as 2 weeks ago getting boat ready old inflatable was inflated I knew I had two foam jobs in the boat and another in garage the one in garage looked ok until I pulled on 1 of the straps and it fell apart had been out of the sun so shows you need to inspect regularly, i self service inflatable every 6 months but don't even think about the foam ones need too check more often