AEROTECH 3" Optical Lab mirror lens true GIMBAL Mount + micrometers + 3" IR lens Description: nice true GIMBAL mount removed from R D laser lab allows for nice adjustments around the axis center. It holds 3" lenses (78mm), but with proper adapter you can reduce this diameter to the one you wish (your adapter can be printed with your 3D printer, for instance) Micrometer screws are two-speed. Lens or mirror is fixed in place with a threaded ring. Very fine adjustment allowed. They are very sturdy (HEAVY DUTY). It includes a special 3" laser mirror that seems to pass through blue light (around 530nm) and reflect laser IR light (one side is mirror, the other side seems "diffuse", not mirror-lile surface). Measures: see pics (in mm). At the bottom there are 5,5mm Ø holes that allow it to be fixed to breadboard or platform and a 1/4" tripod threaded hole for easy placement. Condition: normal usage marks. Nice working condition. Micrometers are soft and do their job nicely. Mirror is good for DIY experimentation but not for serious reasearch operations since it is quite damaged (see last pics). Note: these items have been de-greased, cleaned, re-greased (with special oil better than original grease) and checked for missing or damaged parts. Then tested and verified ok. Good functioning is garanteed. OFFERS: feel free to send me offers.