3-3/8" mounting hole, no sender included. New Vintage Programmable speedometers are easy to set-up and can use inputs from virtually any speed sender, OE or aftermarket the units will even accept input from many PCMs, all of this without any converters or conversion boxes. Speedometers feature a remote mount programming button to keep the gauge face clean and real glass lenses. Programmable speedometers are easily calibrated by hitting the button, driving a mile and hitting the button again, it's as straightforward as that. No confusing DIP switches. Calibration is easily accomplished any time tires or gears are changed. Our speedometers have accumulated over 5,000,000 miles of successful use reflecting their popularity and robustness.