Polypropylene Test Tube Rack for 90 x 13mm Tubes Type_Dual End Primary and secondary copper coils

Primary and secondary copper coils with a sliding iron core and 4mm terminals

and mixed autotrophic-heterotrophic characteristics for protist biology teaching

used to route current down one of two alternative branches in series-parallel circuit investigations

Moving-coil 4-ohm driver in a frame that orients vertically or horizontally

Protozoa and algae survey of 20 slides covers Amoeba

Polypropylene Test Tube Rack for 90 x 13mm Tubes Type_Dual End Primary and secondary copper coilsThree piece polypropylene test tube rack with a fold up grid frame, holding up to 90 tubes at 13 mm in a 10 by 4 inch footprint and disassembling flat for storage.