This depth gauge from RS PRO will help you measure the depth of a space to within ±0.03 mm accuracy. It will measure depths of up to 150 mm (six inches) and give you both imperial and metric readings on its digital display.
The gauge is made from tough and corrosion-resistant hardened stainless steel, making it suitable for heavy-duty applications. It's powered by a SR44/1.55 V silver oxide battery, so there's no need to plug it in. A knurled locking screw makes it easy to fix your measurements for greater accuracy. The end of the shaft is also fitted with a hook, which will make it easier for you to align the component accurately.
This gauge meets the American National Standards Institute (ANSI) ESD S20.20:2014 and British Standard (BS) EN 61340-5-1:2007 electrostatic control standards, meaning it won't damage your equipment via electrostatic discharge. It's suitable for general workshop and machine-shop use.

• Accuracy of ±0.03 mm
• Electronic caliper type
• Capacity of 6 in, 150 mm
• Digital display type
• Both imperial and metric
• Stainless-steel material
• Maximum measurement of 150 mm
• Resolution of 0.0005 in, 0.01 mm