HFS (R Pipe pit welding gauge gage Test Ulnar Welder Inspection Pipe Pit Gage Product is precisely made of stainless steel with dimensional readings chemically etched. Range is 0 to 1/2" in 1/64" & .020 Increments Arm Can be Locked in Place at Any Dimension Size: 131 x 65mm (L x W) (approx)