Laser focus height gauge with magnectic base Great for just about any brand co2 laser. Get your focus exactly right, no more guessing. Simply select what mm focus you would like for your project, set it on your material, and drop your laser head down to the desired focus. Size range included is from 4mm to 15mm or 16mm-27mm. Choose your size at checkout or order both. 3d printed so may show some very minor cosmetic inperfections