This compact size digital gauge clearly indicates actual water temperature. Switchable from Fahrenheit to Celsius, and has backlighting. Velcro mounting makes instant installation on any flat surface a snap. Includes clock feature & charges internal battery from sled. A sending unit adaptor is also available. This allows you to tap into any coolant line. Includes clamps. If I can get a group buy of 15 or more on the water temp gauges I will order them. I tried to do this last fall but had problems receiving the gauges. Digital Water Temp Gauge: $99 Water Temp Sending Unit Adaptor: $25 Normal pricing is $120 for the gauge and $40 for the sending unit adaptor.