3" Black Pinhole Screen with 0.6mm Aperture Subject_Chemistry this 15-inch motion-converter model shows

this 15-inch motion-converter model shows the engineering principle behind crankshaft pistons and rotary-to-linear mechanisms

gripping cylindrical items from 15 to 60 mm alongside an integrated boss head for retort rods

Eighteen-inch 25-watt T8 germicidal UV fluorescent replacement tube

High-level peroxide test strips in a 50-strip vial calibrated at 0

brake pedal switch

3" Black Pinhole Screen with 0.6mm Aperture Subject_Chemistry this 15-inch motion-converter model showsBlack 3 inch circular disc 0. 25 inches thick with a 0. 6mm central pinhole, mounted to a total length of 4. 6 inches for clean pinhole imaging and diffraction studies.