Xenon SM SW102 2 two relay light switch - RTurala/Sonoff-Tasmota GitHub Wiki
Also sold as the Mojocraft Wireless Smart Wall Switch 2 Gang: https://www.amazon.com/Mojocraft-Wireless-Sensitive-Compatible-Required/dp/B072JCWH23/ref=sr_1_3?ie=UTF8&qid=1540858092&sr=8-3&keywords=Mojocraft
I didn't spot any headers, but device has a sub-board with an ESP-12 module on it. Solder right to the 3.3V, Ground, TX, RX, and GPIO pins and flash away. I set the device up as a generic device with the following assignments.
- GPIO 3 is button 2
- GPIO 4 is relay 2
- GPIO 12 is button 1
- GPIO 13 is relay 1