Large Ball-Bearing Differential Pulley, 20/30/40/60mm Steps Glass Sets & Apparatus_Organic Chemistry Sets 6 inches for clean pinhole-imaging

6 inches for clean pinhole-imaging and diffraction studies

Machined to equal volume from six different metals

providing the cleanest hand-operated way to make and break a circuit during early electricity instruction with stackable modules

equipping a class for dual-diameter compound-pulley experiments without cord-threading setup

Large Ball-Bearing Differential Pulley, 20/30/40/60mm Steps Glass Sets & Apparatus_Organic Chemistry Sets 6 inches for clean pinhole-imagingFour step large ball bearing differential pulley with 20, 30, 40, and 60mm steps at 6. 5 inches overall, mounted on a 0. 75 inch post for attachment to standard rod and clamp stands.