RTC + I/O expansion board for Arduino

This PCB is for a small project with arduino to add RTC and I/o features to Arduino33IoT. All PCB are exactly made in accordance with our Gerber files and delivered in only 4 days with a very good quality. A great thing, PCBWay allow us to change our Gerber files only few minutes before starting the production ! There staff are very reactive and the instant chat is very useful. This not my first order to PCBWay and all other PCB were made quickly and with excelent quality.