EPIRBs are essential for anyone going offshore, but you have to be able to reach them in the time of need. So instead of permanently mounting the EPIRB bracket to your fiberglass, mount it to the SeaSucker ACR Cat-2 EPIRB Mount, so you can take it off when you don't need it or move it to where you can quickly reach it. The mounting surface is laser-etched to visually show you where/how to install and pre-drilled for your convenience. EPIRB, EPIRB bracket, and mounting hardware are NOT included.• Measures 4"L x 4.5"W x 2.5"D• Compatible with all ACR CAT-2 models• Mounting surface is laser-etched to visually show you where to install your EPIRB bracket• Pre-drilled for your convenience Mounting surface is laser-etched to visually show you where to install your bracket Pre-drilled for convenience Measures 4""L x 4.5""W x 2.5""D