Long Reach Dial Thickness Gage This versatile Large OD measuring gage for hole diameters, groove thickness, tube thickness, and hard to reach dimensions. Make for fast, accurate, and repeatable measuring. Features include... 2" - 4" Measuring Range 0.001" Graduation 6.57" Max Measuring Depth 1.18" Upper Contact Point Length .9" Lower Contact Point Length 0.196" / 5mm dia Ball on both tips