Specially designed for the needs of automotive and marine racing. The 2-1/4² or 1-1/2² diameter face is calibrated in 10 degree increments. No Wires, senders or cables to install. A 3/8² N.P.T. male fitting on the bottom ³plugs² right into the block, heads, radiator or anywhere along cooling system. Temperature probe gives direct and actual readout at source. Adapts to any engine. Water outlet sold separately.