Hand-Crank Centrifuge, 4 Tubes Subject_Physical Science the 90-45-45-degree geometry serving as

the 90-45-45-degree geometry serving as a precision turning element for total internal reflection and beam-redirection in introductory optics

Three-part life-size digestive tract model with a removable stomach half exposes esophagus

Half-size digestive system model fits smaller class benches while preserving the full esophagus-to-rectum path and accessory organ anatomy in two removable parts

and commutator assemblies for direct observation of each component

laboratories

Hand-Crank Centrifuge, 4 Tubes Subject_Physical Science the 90-45-45-degree geometry serving asHand cranked for field use and low cost classrooms, this die cast single speed centrifuge spins four 15 mL tubes for basic demonstrations of centrifugal separation.