Id_Opaque in MicroProfiler - What is it?

I am currently assisting in development for a large FNaF game and came across something in the MicroProfiler called “Id_Opaque”. What determines it, and how do I lower its impact on the GPU? I have heard that it can be related to complicated meshes with too many tris, but do Parts influence it? Does CanTouch and CanCollide have any effect?

Any help would be greatly appreciated. :slight_smile: