This is a Lifebuoy icon. We've made it in iOS style, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 12,800 icons, all in the same style and quality.
The Icon for Lifebuoy is a round circular ring. There are four rectangular pieces on top of the ring, evenly spaced at the top and bottom and left and right. The ring is on top of an object with rounded corners that make half circles between each rectangular piece.