7-Piece Acrylic Blocks Set, 15mm Thick, with Wooden Storage Subcategory_Alternative Energy 25-inch Magdeburg-hemisphere suction cups with

25-inch Magdeburg-hemisphere suction cups with release stubs

Dual metric and imperial markings on this PVC-coated fiberglass thirty-meter tape measure

teaching a whole classroom the principles of vernier-scale reading before students use benchtop-sized calipers

the elongated triangular geometry handling longer ray paths for total internal reflection and beam-redirection optics

converging and diverging meniscus

7-Piece Acrylic Blocks Set, 15mm Thick, with Wooden Storage Subcategory_Alternative Energy 25-inch Magdeburg-hemisphere suction cups withSeven piece acrylic blocks set at 15mm thickness with all faces polished, the wooden storage box housing the slimmer format optics shapes for ray box friendly experiments.