Testing BLK BOX 4 layer ESP board to take advantage of it's onboard U.FL connector for external antenna mounting on my solar controller enclosure, its pins are the same as the ESP-01 with the exception there are two more IO's added on one end for GPIO12/ADC (jumper selection) and GPIO14

https://www.tindie.com/products/blkbox/4-layer-esp8266-wifi-module/

Photos of the module Installed for testing a Solid State Relay