Features:The protective glass kit to lens, used compatible the protective glass replacement of 20W optical power (X20S20A20 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, rotateclockwise to install the new focusing lens, and finally tear off the dustproof sticker on the focusing lensFine 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 BQuantity: 2pcscompatible: atomstack A20ProS20ProX20Pro laser,XT30S40 module and M100 module internal focusing mirrorPacking List:2 x Window Lens (Type B)