This automatic aerator control provides a source of oxygen-rich water to your live well automatically. This unit features a solid-state timer with adjustable off times to adjust to varying conditions. Easily adaptable to existing systems. Requires a 3" diameter round hole or a 2 1/2" square hole for mounting. Simply connect wiring according to instructions provided. Front panel is 3 1/4 x 3 1/4 and requires only 3" behind panel. This is the only timer on the market that will handle a high capacity pumps current draw. Fully potted to be waterproof.