ACR C-Strobe Life Preserver Signaling Emergency Strobe Omni-directional strobe light visible up to 2 miles. Slim, lightweight, waterproof case. Operates on 2 "AA" alkaline or 1.5V lithium batteries. Operating life - more than 8 hours continuous @ -1 C. (30 F.). Meets SOLAS requirements; USCG 161/.012/41/0, 161/.112/41/0 approved; CE.