Awesome project with hardware, this is what I like.
Yes thank for your advice, the device called "Pundi X POS Device"
There are some menus in this cool device, such as Top-Up for Cryptocurrency (Bitcoin, Ethereum, PXS, etc), Top-Up for E-Wallet, Top-Up Phone Credit, Purchase Electricity,etc. Pundi X POS device has a small size and mobility is very high. Here is another picture of the device.
This battery can last for 8–24 hours and you can use the power supply directly while using the device.
Wireless, GSM, and Phone Line is also supported.
Still want to know more about this device? Stay tuned!