Wards Essentials Trebuchet Kit, Material: High quality precision-cut Birch verner pure bond plywood, Designed to be safe and robust, Dry firings and heavy projectiles are no problem, Holes are pre drilled, Medieval weapons, engineering, and physics, Beam arm: 21in
Breast cancer risk kit, genes and the environment, Contains: Student instructions, Graduated medicine cup, My Family Pedigree, Simulated BRCA1 Genetic Test shee, Stirrer, Breast Cancer Risks-What Science Knows, DNA Stain, 3 Bags of beads
Slit, Five single slits of different widths in a slide frame. Specifications: Slit widths: 0.1/ 0.2/ 0.4/ 0.8/ 1.6 mm, Dimensions: 50x50 mm2, Weight: 0.02 kg