The Alpha Series boasts some smart and ideal features: Quick Change Precision Optics Lens No Fog Anti-Scratch Injection Molded Single Lens Two Piece Frame Design Tear Off Posts Quick Change Removable Strap 50mm Sublimated Non-Slip Strap Sweat Channel Built Into the Frame OTG Frame Design (wear over your glasses) Only Goggle With Quick-Change Lens Under $50 Only Goggle With Quick-Change Strap Under $50 Best Fit Guarantee