Folding Hardwood Ruler, 0.5m, Millimeters and Inches Capacity_10000mL and 2 quadruple pulleys on

and 2 quadruple pulleys on a heavy composite base with capstan

and economic insect biology for entomology and textile studies teaching

measuring oxygen uptake and carbon dioxide release in biology experiments

ground polished edges and optically worked surfaces giving long-bench divergence flexibility in refraction work

Pairs 100 by 75mm with 18mm thickness on an acrylic rectangular refraction block

Folding Hardwood Ruler, 0.5m, Millimeters and Inches Capacity_10000mL and 2 quadruple pulleys onBoldface graduations in millimeters on one edge and inches on the reverse of this folding hardwood half meter ruler, fold compact for storage in physics, math, and shop classrooms.