The default 2" mirror size fits a set of 2" craft mirrors sold in sets of 60 at Amazon: https://www.amazon.com/gp/product/B07T8YJQZS Other sizes exist and this design is intended to adjust reasonably to other mirror sizes within reason. Thick glass mirrors, however, will probably result in "ghosting" on the resulting image as there will be reflections off both the front surface and the rear mirror surface, as well as a green tint that will be more pronounced the thicker the glass. I print in PETG with 20% infill and .3mm layers. The layers are actually used as a ratcheting retention device, so do not smooth the layers out around the axle. Snap the two halves together, oriented as printed and moved toward each other. The parts should splay apart a bit; this is by design to hold the angle you set. Use double-sized tape, epoxy, hot glue, or super glue to attach the mirror only to the center of the space. Don't fill the whole space with glue. The mirror should fit inside the registration box. Gently slip the back piece onto the top of the monitor, centered on the camera, making sure not to obscure or damage the camera. Then, since you purchased a 60-pack of mirrors, make 59 more of these for your friends, family, and all their teachers. Just get measurements for their laptops first!