The Hammar H20E is activated by water pressure which will automatically release the EPIRB Instead of the rope sling a specially developed plastic bolt secures the EPIRB which will be cut when the HRU is activated Features. Release depth 1540 meters. Bolt nut and washers shall be replaced when installing a new Hammar H20E. USCGSOLAS Approval BV MED USCG Section 6Specifications. Dimensions 6 6 4 in. Weight 1 lbs