Lens Holder for 50mm Diameter Lens or Mirror Item Type_Tongs 5-inch hollow glass prism with

5-inch hollow glass prism with a stopper

the smaller-tube counterpart to the 300x44mm standard rheostats with the same constantan-winding construction

a 50mm double-convex glass lens spanning 300-1000mm focal lengths gives projection-style optics setups a single range-rated element

Wood-based hydrostatic balance with two long pans and one short pan adjustable along a central column

sized for color-coded bench wiring at the positive rail

Lens Holder for 50mm Diameter Lens or Mirror Item Type_Tongs 5-inch hollow glass prism withVersatile holder accepting either a 50mm diameter lens or mirror, the dual purpose mount giving optics setups one fewer accessory to track across reflection and refraction experiments.