RGB/CMY Mounted Color Filter Set, 50 x 50mm, 6-Piece Racks & Stands_Flask Stands Rotary-knob resistance substitution board offering

Rotary-knob resistance substitution board offering twelve discrete values from 33 ohms to 10M ohms with 4mm lead connections

holding under at least 100 Newtons of separation force after hand-evacuation of the air between them

and physics principles in classroom investigations

Polished beech wood test tube rack with twelve vertical holes sized for tubes up to 28 mm diameter

RGB/CMY Mounted Color Filter Set, 50 x 50mm, 6-Piece Racks & Stands_Flask Stands Rotary-knob resistance substitution board offeringThree primaries (red, blue, green) and three secondaries (cyan, magenta, yellow) sit in 50 x 50mm mounts, supporting both additive and subtractive color demonstrations in optical box setups.