Laser Hieght Spacer

I purchased a 5500mW laser/cnc engraver and got tired of focusing the laser every time I changed the thing to be laser engraved so I 3D printed this spacer. I place it on the material to be lasered and the top of it goes on the bottom of the laser/spindle holder. I just adjust the Z axis until the bottom of the spindle holder sits gently on this spacer. This makes things a bit easier.