85mm / 3.3in Boat Tachometer Sensor IP67 Tacho Gauge 12V / 24V Red Light with LCD Display Service Hour Meter 3000 RPMSilver Frame Black Dial Condition: Item Type: Tachometer Optional Color: Silver Frame Black Dial, Silver Frame White Dial Tachometer Sensor Model: M18 x 1.5 Tachometer Sensor: M16 x 1.5 Tachometer sensor Materials: Stainless steel + nickel plated plastic Operating Current: ≤60MA Operating Voltage: 12V / 24 Range: 0-3KRPM Input Signal: Additional signal from tachometer sensor, engine, alternator, ignition coil, crankshaft sensor, etc. Adjustable Speed Ratio: 1-300 Protection Level: IP67, the whole body is completely waterproof Red Background Application Mode: LCD screen, stepper motor, high precision Mounting Hole: Approx.85mm/3.3in Instructions: Before installation, firstly open a hole (diameter: 85-87mm/3.3-3.4in) of the panel, make sure there is a gap with (70mm / 2.8in panel backyard) as well. Put the meter in the hole. Mount the caliper in the hole, rotate the back cover after adjusting it.