Review on Enhanced SEO: 12-Volt Dash Socket Plug by Blue Sea Systems (Model 1015-BSS) by Joseph Rasmussen

Excellent build quality but a few things to watch out for. I bought the version with USB charger, the physical characteristics of the plug are identical. The mounting hole should be 1-1/8" or 29mm in diameter, but if you simply drill a hole and bolt it down, the unit will still be able to rotate freely if the rear mounted bolt loosens. The jig has two shallow cuts along the cylindrical body as seen in the figures. I had to cut the exact shape, nearly a 1-1/8" circle with an uncut flat top and bottom to prevent rotation. Very annoying. The supplied frame only covers the front of the device and does not hinder its rotation. It should be attached to your panel with 2 screws. This makes the installation a little more presentable and adds some protection from sea spray. (Bezel installation is optional.) I think 1/4" connectors require crimp tails. Plug supplied with replaceable 1-1/4" (30mm) 10A glass fuse. Screw terminals.