This design is a holder arm for the "Filawarmer" from The Virtual Foundry. I use it with my spool holder system (https://www.thingiverse.com/thing:5253211).
This arm attaches to an aluminum 20*20 profile to hold the heater in a fixed position.
To build this model you will need a M4 hex head 20mm screw, one M4 nut, one plus one M5 screw and a T nut to attach to the aluminum profile.