Rod-style digital depth gauges have a spindle that travels down the length of the slot, step, hole, or projection being measured. When the spindle of fixed or adjustable length reaches the bottom, the length measurement is shown on the LCD display that’s fixed to the frame of the gauge. Digital depth gauges are the most accurate of depth gauge types. Blade-style digital depth gauges have a blade that travels into a bore or feature perpendicular to the base. They may have a tip designed for notches or grooves as well as flat contact. These digital depth gauges provide inch and metric readings on an easy-to-read LCD display.