Not sure on the day count today, pulled them out, they have expanded quite a bit, really soft on the ends, tossed the other two of the set into the juice. These were hard enough to use as jackstands LOL so nothing lost in this experiment. The ones in front are the un altered two of the set of 4, pretty sure these were on my K3 when I got it, would guess they are at least as old as mid 1980's vintage.