Hartley's Rotatable Optical Disc Material_Muslin a step up from the

a step up from the 70mm model with extended pole separation that gives field-mapping experiments more room along the magnet axis

Hard-plastic 13x13-inch Worcester circuit board with 12 metal poles and 4 banana terminals

9-piece organic chemistry and distillation glassware set provides comprehensive apparatus for laboratory synthesis and separation procedures

and 26 SWG - sized as the matched replacement set for the PH0730 sonometer

Hartley's Rotatable Optical Disc Material_Muslin a step up from the230mm disc graduated 0 360 degrees in 1 degree steps locks in any position alongside a rotatable lamp house and six magnetic acrylic elements for full ray tracing studies of reflection and refraction.