ESP-01SR — Ai-Thinker
ESP8266 WiFi module, 8MB flash, PCB antenna, tape & reel, 2500 pcs

Category: Module

Pricing
  LCSC         $0.83
  Mouser       $1.05
  DigiKey      $1.04
  Farnell      $1.13

Manufacturer: https://www.ai-thinker.com