I am lucky enough to get my hands on a Realistic TRC-86, the walkie talkie they used in the series. Not sure if it works but just to have as display is
TESTEDVintage Realistic Walkie Talkie TRC-219 3-Channel CB Stranger Things Mint | eBay
Classic CB HT's (walkie talkies)
Vintage Walkie Talkie - REALISTIC TRC 219 used by Mike Wheeler (Finn Wolfhard) in Stranger Things | Spotern