Wooden Test Tube Support with Draining Pins, 6-Place Science at Home 25-inch gear train simple-machine model

25-inch gear train simple-machine model arrives ready to use with no assembly required

Pairs 50mm of aperture with a 200mm focal length on a convex glass surface

Rat dissection model demonstrates rodent anatomy

accepting interchangeable PH1118 scales for AC/DC ammeter or voltmeter use

Long-focal double-convex glass lens at 75mm diameter and 500mm focal length

Wooden Test Tube Support with Draining Pins, 6-Place Science at Home 25-inch gear train simple-machine modelDraining pins paired with a turned post hardwood frame give this six place test tube support inverted drying plus upright storage for tubes up to 19 mm across.