Adjustable V-Blocks are a versatile tool for precisely measuring and positioning components. Their adjustable design allows for reliable and accurate handling of a wide range of materials and objects. These precision made Adjustable V-Blocks performs all of the functions normally requiring the use of various blocks, shims, or non-precision machinist jacks. Supports single and multiple diameter shafts, bars, etc. by quickly adjusting height. Features include... Wide angle 120° V with 2-3/4" opening accepts 3/16 to 5" diameters. High Precision Adjustable V-Block Set 2pcs included in set Total height adjustment: 9/16", .050" per revolution, 0.001" dial increments Position lock prevents vibration creeping. Base Dimension: 4" W x 1-3/4" L V opening: 2-3/4", 13/16" wide Height: approximately 3" closed, 3.75" opened. Top Flats ground parallel to base.