Building with your hands is something that will never go out of style. Seeing a product you helped to create work as intended gives a sense of pride that is unmatched. Ensure your parallels are accurate, your pieces are positioned properly, and your materials are lined up with the ABN 123 Machinist Blocks. 5 matched pairs of setup blocks are precisely milled to 1 x 2 x 3in (2.54 x 5.08 x 7.62cm) with accurate 90-degree angles down to .0002in (0.005mm) to ensure meticulous detail. Outfitted with 5 threaded 3/8-16 holes and 18 untapped holes, you are able to clamp or drill through these measuring blocks at almost any angle. Each matched pair weighs in at 2.07lbs (0.94kg) to easily carry around in your pocket so you are always prepared for the task at hand. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.