HydroFix™ Hydrostatic Release Unit (HRU)The HydroFix™ Hydrostatic Release Unit (HRU) is a patented rod system that allows a beacon to be quickly and reliably released from a Category I bracket when submerged in water between  4.9′ to 13.1′ (1.5 to 4 M.)   Does not rely on a battery, blade or pyrotechnic device to release the beacon.  This advantage allows for a quick, seamless and reliable release in an emergency.*This is a date-stamped product and must be replaced every 2 years from the date of installation or 4 years from the date of manufacture.  Compatible With:ACR Sea Shelter,  Sea Shelter2 and Sea Shelter3 brackets Features:Easily replaceable100% factory testedTechnical Specifications:Dimensions –  2.5\