TUSA M2001S Paragon professional divers mask. The Reinforced TRI-MIX frame, Freedom Technology with Fit II, and the UV 420 Lens Treatment with AR and CrystalView Optical Glass which helps you dive with eye protection and ultimate clarity. TRI-MIX Frame. Freedom Technology with Fit II. UV 420 Lens Treatment Anti-Reflective Lens CrystalView Optical Glass. Angle Strap Adjustor with Side Hold. Offset Buckle. Corrective lens available: MC2001SA Non-Reflective lens available: ML2001S