VERITAS - Spacer blocks set usfull for setting fence distances on stationery machines and numerous other applications where a spacer block takes the place a repetitive (and comparatively innacurate) measuring using steel rules etc. The large, precison milled, steel parent block is 25 x 50 x 75mm and accurate to within a tolerance of 0.018mm. There are 3 vinyl blocks, 2 of 0.5 and one of 1.0mm and five aluminium pieces 2, 4, 8 and 2 pieces of 16mm which used together offer a range of 0.5 to 123mm.