A patented rod system 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. Note that 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. Easily replaceable 100% factory tested Patent Number: 7,435,148 Fits: ACR Sea Shelter,™ Sea Shelter™2 and Sea Shelter™3 brackets Size : 2.5 x 3.4 x 2.0” (6.3 x 8.6 x 5.0 cm) Weight : 3.3 oz (93.6 g)