Specifications: Name: Mini E-PaperBand: 2.4GHz ISMBuilt-In Battery Model: 350829Capacity: 100mAVoltage: 3.7VFeature:MiNi E-Paper Shield is MiNi E-Paper's nRF24L01 2.4G Wireless Transceiver Module expansion board, which is a 2.4GHz ISM Band available worldwide.MiNi E-Paper Shield back antenna can be ..