Please be advised that this radio configuration (RC3) is not adapted for United States.
WF931 is a Down & Uplink module for the Japan region. Small size of 13 x 13 x 2.3mm works well on your development with small sized products. External antenna intended as well as SMK recommended built-in antenna pattern design available. Simply operates through UART with AT commands.
End Product Certificate M_0031_1CE0_01
Dimensions (in mm): 13 x 13 x 2.3
Max Tx Radiated Power: +13 dBm
Rx Sensitivity: -125 dBm
Power Supply: From 2.2V to 3.6V
Tx: 45 mA
Rx: 15 mA
Idle: 1.8 μA
A connector for an external antenna is available