This is a M2.5 nut holder to assist with the assembly of the most excellent Jet Engine model published by CATIAV5FTW https://www.thingiverse.com/thing:1327093 . One already exists for a M3 nut, this is for the M2.5 as specified in the build instructions. This tool will only take minutes to print, but it will make assembling the Fan Stator Casing to the HP Core Casing a breeze. It is really fiddly to try and get the nuts to take on the bolts using tweezers.