May I add that it is a good idea to cover the cylinder right after it has been taken out. I had one explode 10 minutes sitting on the floor. 1/4 glass shot out covering my one yr old baby girl in her bouncy chair. Kyle Moore is the one that told me to put a heavy blanket such as a moving blanket over said cylinder for at least 24 hours. Daughter was fine, wife well - Just my experience of 35 yrs.