US$ 17.95
and ray-tracing demos
Simultaneous AC and DC output on this low-voltage power supply
an Erlenmeyer flask
Hand-painted 4-part human brain model separates into cortical hemispheres and brain-stem regions for lobed-anatomy teaching at introductory biology levels
Working Steam Engine Model with Piston and Slide Valve Stock Type_Stocked and ray-tracing demosCutaway working steam engine model with piston, slide valve, and link motion reversing mechanism, the flywheel light enough to drive by breath for hands on reciprocating engine study.