This International Standard specifies performance and testing requirements for hydrostatic release units used in conjunction with float-free lifesaving appliances including inflatable liferafts and Emergency Position Indicating Radio Beacons (EPIRB 's). Hydrostatic release units which comply with this International Standard and which have been formally approved by the cognizant Maritime Safety Administration may be considered to comply with the 1974 Safety Of Life At Sea Convention (SOLAS 74) and the IMO Life-Saving Appliances Code, as amended.