2450 Battery you need - https://amzn.to/2Ksdp4M
Protective key/fob cover - https://amzn.to/3mfvZ35

Here is the all new key fob for the 2021 Chevrolet Tahoe and Suburban! The steps to swap out your dead or weak / dying battery are fairly straightforward. You do not need any tools at all. Use the mechanical emergency key to drop off the back and gain easy access to your dead battery. Replace with the + side facing up and you're all set! Hope this was helpful!

GM Part Number: 13541565
FCC ID:
Frequency: 433 MHz
Battery: CR2450
Emergency insert key: original PN 13536164
Reusable: No
On Board Programming: No
6 Buttons: Lock, Unlock, Remote engine start, Power door release (back gate), Glass hatch release, Panic alarm
This remote also fits:

2020 2021 2022 20 21 22 Chevrolet Suburban
2020 2021 2022 20 21 22 Chevrolet Tahoe
Also fits the GMC Yukon