These Lens Savers® are for use with the 1.5" adapter (0026-6002) for Bystronic systems in excess of 3000 watts. They can be used with both 5.0" and 7.5" focal lengths. They are sold in packs of 10. The adapter enables users of Bystronic cutting systems to use Lens Savers® under high pressure. The components of the adapter fit inside of the Bystronic OEM lens mount. The adapter provides means to accommodate the additional space taken by the Lens Savers® window when it is placed inside of the Bystronic OEM lens mount. It also allows the assist gas pressure to pass into a cavity between the Lens Savers® window and the lens, which results in the pressure on both sides of the window being equalized. The assist gas passes through holes drilled around the perimeter of the window outside of the optical path of the laser beam. ICL's patent pending pressure equalization method prevents the Lens Savers® window from breaking by providing an environment in which the pressure around the windows is equalized.