Intercom-capable phones

I need to have a pair of phones capable of calling each other for ME 262 this saturday, to represent out calls using the landline at the event. Does anyone have something like this that I could borrow?

NZLARPS has the set of four 2-way radios, is this sufficient?

I’m pretty sure those are missing. Also, it would help if they were actually phones, radios don’t operate the same way.