I would add do not scrimp on buying one even if it says Coast Guard approved. My grand kids like swimming with on on and with constant use. a cheap one turns into trash, I got the west marine ones and the materials are very good and dry out and store very well. and become Hand me downs for many years. Bill
Mine is a auto inflatable that I used Kayaking a full one was to hot to wear. Only ones did it inflate when I flipped in the surf return
Scared the heck out of me when it went off. the $30. for a recharge Kit.
.