Ray Box with Magnetic Base, 12V 21W Lab Supplies_Thermometers and has an inner diameter

and has an inner diameter of 3

Standard rheostat at 37 ohms and 3

Racked display of fourteen precision-machined stainless steel slotted masses totaling 1110 grams from 1 to 100 gram pieces

and mechanical advantage studies in physics

Hand-painted 4-part human brain model separates into cortical hemispheres and brain-stem regions for lobed-anatomy teaching at introductory biology levels

Ray Box with Magnetic Base, 12V 21W Lab Supplies_Thermometers and has an inner diameterMagnetic base anchors the metal cased unit to benches and steel boards, while variable focus produces five parallel beams that a shutter masks selectively. Ships with a 12V 21W bulb.