The laminated glass lenses have a scratch resistant coating and offer 99% UV protection. The split style is in keeping with the original goggles dating back to world war II, and give a great field of vision. The lenses are held inside a brass channel that slots inside the goggle frame and is then retained by attaching the headband clip. This allows you to quickly and easily replace the lenses. Suitable for Mark 4, Mark 8, Mark 9 and Mark 49 googles.