WSM
Experienced Member
Details are in the eBay listing for this 2"x2"x0.6" system with USB for power and two serial ports. I'm the original designer / builder of this system and it's my listing. I'm only building a few of these occassionally and putting them on eBay but I'll also consider direct purchase requests.
https://www.ebay.com/itm/184330814661
https://www.ebay.com/itm/184330814661