RGB/CMY Mounted Color Filter Set, 50 x 50mm, 6-Piece Racks & Stands_Flask Stands tightened with an Allen wrench

tightened with an Allen wrench for constructing lattice frameworks on laboratory benches

the flywheel light enough to drive by breath for hands-on reciprocating-engine study

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

Speed-controlled 6V motor driving two cams pumps four spring-mass systems at any chosen frequency

75-inch height range for bench apparatus

RGB/CMY Mounted Color Filter Set, 50 x 50mm, 6-Piece Racks & Stands_Flask Stands tightened with an Allen wrenchThree 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.