One Pair 1 2 3 Precision Blocks No Hole 2 PCS 2 PC 1 2 3 Metal Blocks NO HOLE ; Made of hardened tool steel and precision ground on all six sides Size: 1 x 2 x 3";Size within +/- .0002";Flatness and parallelism within .0002" Squareness on all sides is 0.0003" per inch;Pairs are matched to a tolerance of 0.0002" Cross drilling design allows efficient use of lower weight with maximum strength Quantity: 2 PCS ; Unit weight: 3.40 lb (total for 2 pc) ; Heat treat and hardness 56 to 60 RC