14-Piece Solid Brass Slotted Mass Set Biology_Botany 8mm rod attachment and a

8mm rod attachment and a centered 50mm aperture together hold a lens square against an optical-bench rail for repeatable refraction

this resistor module on a demonstration base with 4mm plug connections drops into series with bulbs and LEDs in student circuits

125 inch Alnico horseshoe

this Alnico U-shape carries 45mm pole spacing for compact-bench field demonstrations and motor-effect setups

14-Piece Solid Brass Slotted Mass Set Biology_Botany 8mm rod attachment and aBrass fourteen piece slotted mass set machined across 1 to 500 gram pieces at a 1110 gram total, supplied on a plastic and metal rack with a carrying handle for classroom transport.