6PK Plano Mirror, 6 x 4 Inch - Glass

This six-pack contains plane glass mirrors measuring 6 by 4 inches at 2mm thickness. Plano means flat, and because the reflecting surface has no curvature the angle of reflection equals the angle of incidence at every point on the surface. The rectangular format suits ray box work, where a mirror stands on its edge against a printed protractor and light is traced in and out. At 6 by 4 inches the surface catches several rays at once and shows image formation, symmetry, and lateral inversion. The 2mm thickness balances strength against weight, giving enough rigidity to stand and be handled without adding bulk.