Want to work on your own night vision? Well we have the tools you need. This is a three piece set. 
 
Tube retaining ring wrench
Close focus stop ring wrench
Infinite focus stop/Eyepiece lock ring spanner wrench
 
These tools make assembling night vision with PVS-14 style optics on them easy. Hardly anybody carries these specialized Night Vision-specific tools anymore, but we do!