Smartfind S20 SRS AIS MOBMcMurdo's Smartfind S20 Survivor Recovery System (SRS) is a personal AIS device worn on your lifejacket and activated by sliding off the safety tab and lifting the arming cap to deploy the antenna. The compact, lightweight unit sends alert messages, GPS position and a special identity code directly to AIS receivers within approximately a 4-mile radius. A flashing LED light aids location at night.A unique, built-in, high precision GPS receiver - which updates every 60 seconds - assures accuracy of the data transmitted from the S20 SRS. With precise location, distance and bearing data, fellow crew members (and nearby AIS-enabled receivers) receive all the information they need to locate the position of the person in difficulty and to enable a speedy recovery. The S20 SRS will transmit continuously for up to 24 hours and has a 7-year battery storage life. It is made of ultra durable ABS and is waterproof to 5 meters.Features:Compact and lightweightSends alert messages, GPS position and a special identity code directly to AIS receiversSends to approximately a 4-mile radiusBuilt-in, high precision GPS receiverSRS transmits continuously for up to 24 hours7-year battery storage lifeWaterproof to 5 meters