Description: 【Specification】: 11 Hole 1 x 2 x 3 Inch parallel blocks, 5/16" 18 thread 【Premium Material】: The 1x2x3 blocks are made of hardened steel material, high strength, wear resistant, sturdy, and ensures a long time to use 【High Performance】: Professional machinist set up blocks with high parallelism and verticality, accurate grinding, accurate positioning, improving efficiency 【Applications】: The 1x2x3 blocks for calibrating equipment, used for clamping support and calibrating work 【Package Including】: The package includes 1 pair/2 pieces of 1x2x3 blocks Specification: Material: Steel Size Chart: 10.5 cm x 8 cm x 2.6 cm/4.13 inch x 3.15 inch x 1.02 inch Package Includes: 1 Pair/2 Pieces Parallel Blocks  Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.