Prisms Glass Equilateral, Size 50 mm-EIS-PH0556C offers a thoughtfully designed, durable resource for hands-on learning. 60 degree angles 1.96" sides (50mm) Non optically worked glass Slightly beveled edges This non-optically worked glass equilateral prism has slightly beveled edges and 60x60x60 degree angles. Its sides are 1.96" each or 50mm.