Engineered and tested to ensure it can withstand even the harshest elements. Requires no subscription for use in a wide variety of environments. Whether on land, at sea, or in the air, trust that the ResQLink's satellite precision and military durability puts rescue in the palm of your hands. 4.52" (L) x 2.03" (W) x 1.49" (D) GPS and Galileo GNSSBuilt-In BuoyancyStrobe and Infrared StrobeGlobal CoverageMEOSAR CompatibleSmall and lightweight5 year battery life24+ hours Operational Life****Based on test report from accredited laboratory