This release is deployed underwater and contains the receiver plus a micro computer and batteries and holds a replaceable release link with a pull pin for replacement. It turns on automatically when it is placed in the ocean by means of water contact to the two metal posts on each side of the transducer. This release has a unique 4 digit identification number that has been assigned to it by the factory. This identification number is entered into the topside acoustic release interrogator (ARI-60) when a command is sent. When the release command is received the unit applies its full battery voltage to the link (pos) and the ‘coil’ (neg) for 15 minutes. This causes the small hoops of metal to erode away effecting the release. This release unit has a single green LED that flashes once per 10 seconds when the unit is on and listening. There is a checkout command that can be sent to cause the unit to switch on the erosion voltage for only 10 seconds which is useful for checkout. (Note: This release works in ocean water and typical bay water. It will not work in fresh water since the electrolytic erosion will not occur at a fast enough rate).