±2.5mA DC Interchangeable Dial for Demonstration Meter Glass Sets & Apparatus_Organic Chemistry Sets Wooden fulcrum-balance simple-machine model with

Wooden fulcrum-balance simple-machine model with a sliding pivot

Life-size right lung separates into two parts exposing bronchial tree and alveolar structure

this magnified animal cell model reveals organelle ultrastructure and cellular organization for advanced biology instruction

Binaural stethoscope with PVC tubing provides clear heart and lung sound detection for medical and nursing education

Five-centimeter brass sphere mounted on an ebonite-insulated metal base

±2.5mA DC Interchangeable Dial for Demonstration Meter Glass Sets & Apparatus_Organic Chemistry Sets Wooden fulcrum-balance simple-machine model withPlus or minus 2. 5mA DC interchangeable scale on a 315x115mm laminated panel with integrated shunt, sized to drop into the demonstration meter and reconfigure it as a center zero ammeter.