Are you running out of resources on your Arduino Uno R3? Then this is the replacement for you, this board has a LOT more horsepower in terms of processing speed and hardware peripherals (DMA controller, SERCOM modules.......)
ALL OUR ITEMS ARE LOCALLY STOCKED AND SHIPS IMMEDIATELY!
Dimensional Drawings: http://myosuploads3.banggood.com/products/20200313/20200313033438DIM-SAMD21-M0.pdf
Pin Diagram: http://myosuploads3.banggood.com/products/20200313/20200313033426PINOUT-SAMD21-M0.pdf
Quick Start: https://startingelectronics.org/articles/arduino/wemos-arduino-m0/