Square Boss Head Clamp, Die-Cast Alloy, up to 16mm Rods Foodsafe Double-concave glass lens at 3-inch

Double-concave glass lens at 3-inch diameter and 200mm diverging focal length

Entry-level two-part human skull model separates the skull cap to reveal the cranial cavity for introductory head-anatomy teaching at secondary and college levels

Base-mounted 2-stroke diesel engine model in aluminum and plastic

Enlarged three-times life size with seven separable parts exposing cornea

Triple-parallel plastic pulley with three 50mm wheels on a steel frame with end hooks

Square Boss Head Clamp, Die-Cast Alloy, up to 16mm Rods Foodsafe Double-concave glass lens at 3-inchSquare die cast alloy boss head with metal thumbscrews, gripping square or round rods up to 16 mm and accommodating flat articles like rulers and drawing boards.