This thermostat is an older type, but not so old that the temperature sensor switch is mercury-level based.
It simply is from before the Internet-of-Things era started. Meaning, it's not a smart device.
But it works (see two pictures with information showing in the display.)

Dimensions: 3.75 inches high, 5.5 inches wide. Will stick out from the wall 1 & 5/16 inches.

Has standard connections labeled: G, W, Y, RH, RC
It's been several years since I've swapped out thermostats... but if I remember right, I think RH and RC are both red wires, one for heat and one for cold. The rest of the wires should be green, white and yellow.

Takes two double-A batteries for backup power, so it will not lose its settings in case of power outage.
Batteries included. Possible to swap in fresh batteries without losing settings by replacing only one battery at a time.

Has instructions for setting & adjusting time & temperature set points, et cetera, inside the front cover, which simply snaps on & off.

I live in Scotts Valley, and work in Mountain View.
If you’re in Scotts Valley or Santa Cruz/Felton/Ben Lomond area, we’ll meet at the nearby Starbucks.
If, however, you are anywhere near my commute from Scotts Valley to Mountain View, I should be able to drop off at your location on my way home from work. Or on the way to work if you are out of bed by 6:30 AM.

Rob (just call me Wex) Wexner

Older heater / AC thermostat (Scotts Valley by Vine Hill Rd.)