Question about blender and problem with model

Ok so im totally new with using blender or any modelling program for that matter. I am trying to use a part of a model for a gamemode, which is using clothing pieces that players can equip.

I decompiled a model to take a kneepad from it, and removed everything from the model but this kneepad, I recompile the model and textures and everything work. The problem is that garrysmod is considering this prop an entity which makes it impossible to pick up via our gamemode. Was hoping anyone would know what I am doing wrong here. I want the model to be considered a prop in garrysmod.

Any help or direction with this would be much appreciated. Thanks!