6-Piece Optical Lens Set, 3", Double Convex and Double Concave Physics_Mechanics this motor-generator pairs a split-ring

this motor-generator pairs a split-ring commutator against slip rings with bulb indicators

and bladder in anatomical position

Entry-level two-part human skull model separates the skull cap to reveal the cranial cavity for introductory head-anatomy teaching at secondary and college levels

Plastic-bodied wave apparatus with eccentric discs that drive metal rods up and down as the handle turns

Four-metal 32mm density cube set with hooks in brass

6-Piece Optical Lens Set, 3", Double Convex and Double Concave Physics_Mechanics this motor-generator pairs a split-ringSix piece 3 inch optical lens set combining three double convex and three double concave glass lenses at 200mm, 300mm, and 500mm focal lengths for comparative refraction experiments.