These are Glass Prism for teaching about light refraction and dispersion.
| Order# | Description | Size | 
| 7-909-70 | Equilateral | 25mm x 50mm | 
| 7-909-71 | Equilateral | 25mm x 75mm | 
| 7-909-72 | Equilateral | 25mm x 100mm | 
| 7-909-77 | Equilateral | 25mm x 150mm | 
| 7-909-73 | Right Angle | 32mm x 50mm | 
| 7-909-79 | Equilateral | 3" x 5/16" | 
| 7-909-92 | Equilateral | 42mm x 32mm | 
| 7-909-91 | Right Angle | 100mm x 10mm | 
 
    
             
 
  
 