The Fowler 54-554-630 electronic caliper has a plastic electronic housing with steel arms and hardware, an LCD readout, zero-setting capability, a hold feature, and is spring-loaded. This caliper measures OD for hole diameters and groove and tube thicknesses. The LCD readout shows inches in decimals, fractions or metric readings for versatility when measuring. The knurled lock nut holds the spring-loaded sliding jaw in position when required. The measuring gages arms and hardware are made of steel for durability. The 2" diameter electronic housing is made of plastic. An automatic shut-off feature turns the caliper off after four minutes to prolong battery life. The unit also comes with a plastic case and instructions. Fowler, an American company, manufactures premium inspection and measurement instruments like electronic indicators, calipers, bore gages, and micrometers. The company, founded in 1946, is headquartered in Canton, MA.