Features: The protective glass kit to lens, used for the protective glass replacement of 20W optical power (X20/S20/A20 Pro model) series laser heads, XT30S40 module and M100 laser module, sorting the problems caused by the dirt and damage upon long time use. Installation method: Use a screwdriver or a small hexagonal wrench to remove the air guide cover of the laser, turn counterclockwise to remove the original focusing lens, rotate clockwise to install the new focusing lens, and finally tear off the dust-proof sticker on the focusing lens Fine quality, durable to use. What You Get: 2pcs Window Lens. Any problem, please contact our store. Honor to serve you. Specification: Mode: 20W Laser Module Window Lens - Type B Quantity: 2pcs For: atomstack A20Pro/S20Pro/X20Pro laser, XT30S40 module and M100 module internal focusing mirror Packing List: 2 x Window Lens (Type B)