12-Hole Test Tube Stand for Mixed 30mm and 15mm Tubes, Polyethylene Subcategory_Geology Models a less-common metal reference for

a less-common metal reference for density-investigation comparisons alongside the standard brass

Beech wood test tube rack holds 12 tubes up to 20mm diameter in a 9-inch frame for organized storage during chemistry and biology experiments

5-inch plastic moment-of-inertia disc on a magnetic-base ball bearing

25 inch diameter

Used to dissipate heat during sustained high-current work

12-Hole Test Tube Stand for Mixed 30mm and 15mm Tubes, Polyethylene Subcategory_Geology Models a less-common metal reference forFlat pack polythene test tube stand with six 30 mm and six 15 mm holes, disassembling for easy cleaning between uses in chemistry classrooms and student laboratories.