Guys I know i have seen alot of talk on what to replace the o rings on the robart gear with. After some thought I will stay with O rings from my local fastenall store. about 2.50 for 15 of them. Had thought of a bungey cord, but if it brakes, you have nothing. If one o ring brakes you are still good. unless you slam it in, dont think you will brake all 4 o rings at one time. I do replace mine every year.