[Request] Blank model with a collision sphere

Edit: Someone suggested I use the invisble platform. It doesn't let me delete the thread so please ignore this. Thank you.

I'm trying to use trackables on my map but I need an invisible model. I tried Vex's dummy model (from the caster systme map) but it doesn't work. Someone said that it doesn't work because the model doesn't have a collision sphere. I assume this is a mdl/mdx editing job. Anyone interested is helping me?

I've attached the dummy model if you want to use/edit it. I didn't see anything in the caster system map about if we can use the model or not.