The ResQLink Personal Locator Beacon weighs less than a couple of energy bars and could someday save your life. It uses satellite technology to notify search and rescue of your location in an emergency. This ultra compact emergency beacon weights only 4.6 ounces. With 5 watts of power, the ResQLink Personal Locator Beacon is more likely than other locator devices to reach a satellite in bad weather. Class 2 (non-hazmat) lithium batteries have a shelf life of 5 years. Operation life 24 hours. These batteries should be replaced after use in emergency situations. A satellite test feature lets you confirm that the ResQLink is working properly before you need to activate it. The 66-channel GPS receiver acquires satellites faster when activated than many similar devices. An automatic strobe flashes while the device is activated to help rescue personnel see your location. Three levels of integrated signal technology improve the likelihood that your distress signal will be received. Submersible up to 5m for 1 hour. DOES NOT FLOAT.