When you are using the newly added engineer upgrades on the bell tower, you can upgrade it to a portable phone (IMT frame I think it's called)
It is really not clear what does it do. The description only says it's a frame. I can put it on the back slot, but I can't put items inside like the RTOs. I'm not even sure what it does, the description give no clue, asked mentors and other engis and they didn't know either.
The texture looks like a phone that goes on the back of an RTO. That's why I assumed that it's a phone. I know how to use those as I played that role, yet these can't be used as such. If I click on it, while it's on my back, it just puts it in my hand. If I click on it with my other hand, it switches hand.
I tried everything, even planting it as a C4 as it says it's a mount. Maybe I need to mount it somewhere? I tried to go melee range to a xeno, maybe it's a portable bell? But it does not bing at all like a bell does when xenos go near. Do I need to use a gun so it keeps ringing than?
What does it do??