Driver’s Side Mirror Had Altercation With Carwash

We had just purchased our new (to us) 2014 Infiniti QX80 when we noticed a little dirt on the exterior. No worries, we thought, they have carwashes for this kind of thing. Not knowing about the store mirror button on the driver’s side arm rest, we took the beautiful new car through the car wash. Upon exiting the carwash, our poor driver’s side mirror was dangling by the door that was meant to be supporting it.
Here’s my question. What size screw is holding the mirror to the base? There are three screws. Here are some pictures for reference. (Note: these are screen grabs I took from a video and manual that did not tell me the info I needed)