I purchased 2 of these. Trialed both of them three times each to see it it would self activate. It took many attempts to get these torches to activate. This did not give me the peace of mind I wanted as it was going to go on a child's lifejacket. Item returned. It fits on well to a lifejacket with a self inflating tube. But it not consider well how it would fit on to a life jacket without those.