Optical Lens Set, 2", 6-Piece, Convex and Concave Base Size_9 x 9" Can withstand temperatures up to

Can withstand temperatures up to 135 °C

Urine test strips not included

Pith balls suspended both inside and outside a charged metal cylinder make visible proof that electrostatic charge resides only on the outer surface of a conductor

and enzymatic activity

Optical Lens Set, 2", 6-Piece, Convex and Concave Base Size_9 x 9" Can withstand temperatures up toSPHERICAL Each lens is spherical in shape and measures 2" (50mm) in diameter FOCAL LENGTH VARIETY Converging and diverging focal lengths in 200mm, 300mm and 500mm OPTICALLY WORKED GLASS Made of high quality, optically worked glass. Highly polished with ground edges GREAT FOR PHYSICS CLASSROOMS This optically true lens set is excellent for physics classroom demonstrations in optics and light refraction Set of Six Optically True Concave & Convex Lenses