Material: K9 optical glass. Size: about 20*20*20mm/0.78*0.78*0.78inches. This right-angle optical glass prism is perfect for measuring critical angles and observing reflection.Using two Right Angle Prisms together is ideal for image or beam displacement applications. Good for optics lessons or optics science projects. These have silvering on the diagonal face.
If you want to redirect the beam of light like a camera then they are very good. The downside is that they are silver plated on the long side, so you can't get rainbow colors (be careful!). Good quality.