Precision Parallel & Workstop
Set of precisely machined, paired metal blocks used in machining operations to accurately hold a workpiece at a specific height, ensuring parallelism between the workpiece and the machine bed, typically consisting of multiple pairs of different heights with highly accurate flat surfaces, all within very tight tolerances for precision work; essentially, they are used to maintain consistent alignment and level when clamping a piece in a vise during milling, drilling, or turning operations.