Breakthrough design, there are new breakthroughs, based on ESP-12E.
The new four-layer board design.
The new revision antenna RF performance optimization, communication distance is increased by 30% -50% compared to ESP-12E!
Semi-hole chip technology, the whole IO leads, with metal shielding shell
Passed FCC & CE & RoHS certification
Built-board PCB antenna
4M bytes SPI Flash for programming.