Rectangular Refraction Block, 3" (75mm) x 2" (50mm) x 0.5" (12mm) - Optically Worked Glass - Slightly Beveled Edges - Excellent for Physics Experiments & Photography - Eisco Labs industrial_Oct2022 never out of fashion

never out of fashion

and smooth along the edges

For first use you may need more twisting

which means tray fits any mouth and allows you to whiten the top and bottom teeth at the same time comfortably

Rectangular Refraction Block, 3" (75mm) x 2" (50mm) x 0.5" (12mm) - Optically Worked Glass - Slightly Beveled Edges - Excellent for Physics Experiments & Photography - Eisco Labs industrial_Oct2022 never out of fashionRectangular Refraction Block, 3" (75mm) x 2" (50mm) x 0. 5" (12mm) Optically Worked Glass Slightly Beveled Edges Excellent for Physics Experiments & Photography Eisco Labs Product Features RECTANGULAR BLOCK Rectangular block made from imported optical glass with optically worked surfaces. All angles accurately worked with edges slightly beveled. Bubble free glass 3" LENGTH Block measures 3" long, 1. 5" wide and is 0. 5" thick PHYSICS EXPERIMENTS