Parallel supports made of hardened steel and finely ground in pairs,Parallelism +/- 0.005 mmLength: 150 mmPairs: 7Heightx width per pair: 10 x 3, 12 x 3, 14 x 4, 18 x 6, 24 x 6, 30 x 8, 38 x 8 mmRequired for clamping workpieces in the machine vice during milling.