West Marine Mustang Survival Inflatable PFD without Harness, Ocean Series HIT Md3183 Wm Hydrostatic Inflator Technology (HIT) Works on hydrostatic pressure, inflates when submerged in 4" of water and is not sensitive to humidity, rain or splash Strobe light holder, safety whistle and SOLAS reflective tape Backup oral inflation tube D-ring to attach lanyard to engine emergency stop shut-off switch