These are retainers for holding wire into type G and H Panduit wireways. If you have ever worked with these wireways before, you know how annoying it is when wires won't stay put. These aren't as fancy as the ones made by Panduit, but they get the job done. 

There are 2 files, one is for 1" tall wireway and the other is for 1.5" wireway. These can be printed without supports if they are oriented the way they are in the STL files, just make sure you have good bed adhesion or print with a brim.