Wooden Test Tube Support, 15-Place Glass Sets & Apparatus_Organic Chemistry Sets Extended-range rheostat at 12 ohms

Extended-range rheostat at 12 ohms and 4A on a 200x44mm tube with constantan winding

Designed for larger-volume Snell's-law work

Copper-block plug key switch with two 4mm terminals and a removable plastic-guarded plug

Three-wire setup pairs a 100N spring-balanced string

restoring UV-C output in the compatible goggle sanitizer cabinet once the original lamp reaches end of service life

Wooden Test Tube Support, 15-Place Glass Sets & Apparatus_Organic Chemistry Sets Extended-range rheostat at 12 ohmsSolid hardwood 15 place test tube rack milled from a single block with slotted holes, keeping tubes up to 13 mm upright on the bench during student experiments.