Double Convex Glass Lens, 50mm Diameter, 300-1000mm Focal Length Range Grade_Food Grade Low temperature gradient- can withstand

Low temperature gradient- can withstand high temperatures & thermal shocks

Used as the positive-rail counterpart to the long black lead

Blue 300mm 2mm-stackable lead with nickel-plated split-hollow pins

Tensioner pulley keeps chain engagement consistent on this hand-cranked chain drive

Designed to measure Planck's constant through the photoelectric effect

Double Convex Glass Lens, 50mm Diameter, 300-1000mm Focal Length Range Grade_Food Grade Low temperature gradient- can withstandBuilt for long bench convergence flexibility, a 50mm double convex glass lens spanning 300 1000mm focal lengths gives projection style optics setups a single range rated element.