Nozzle Holder attaches to Prusa MK3 series. Separate size inserts for easy identification. Also holds wrench from E3D Fun Pack.
Insert Sizes/Types
.10 .15 .25 .30 .35 .40 .50 .60 .80 1.0 HS SS NP C B OR
Print hole side down
Inserts need to be printed with smaller nozzle like .25 and multicolor for better readability.
The author hasn't provided the model origin yet.