Basics: Project 066d ESP8266 ESP-12E WI FI module (LoLin NODEMCU V3), 5V relay module - protected IO at Acoptex.com / ACOPTEX.COM
ESP8266 ESP-07 ESP07 Wifi Serial Transceiver Wireless Board Module 3.3V-5V 8N1 TTL UART Port Controller for Arduino R3 - AliExpress
DM Strong ESP8266 Wifi Development Board CH340 Micro USB 3.3/5V Compat – diymore
ESP8266 ESP-01S 5V Wifi Relay Module Remote Control Switch Phone APP For Smart – ASA College: Florida
Wholesale ESP8266 ESP-01S 5V WiFi Relay Module Things Smart Home Remote Control Switch for Arduino Phone APP ESP01S Wireless WIFI Module From m.alibaba.com
Ask Hackaday: Is The ESP8266 5V Tolerant? | Hackaday
Esp8266 Esp-01s 5v Wifi Relay Module Things Smart Home Remote Control Switch For Arduino Phone App Esp01s Wireless Wifi Module - Integrated Circuits - AliExpress
Controlling a 5V relay with an ESP8266 : r/esp8266
Amazon.com: Acxico 2 pcs ESP8266 ESP-01S + 5V WiFi Relay Module Smart Home Remote Control Unlock Board : Electronics
Ask Hackaday: Is The ESP8266 5V Tolerant? | Hackaday