DSD TECH HM-10 Bluetooth 4.0 BLE iBeacon UART Module with 4PIN Base Board for Arduino UNO R3 Mega 2560 Nano

Amazon.com Price: $10.99 (as of 06/05/2021 15:14 PST- Details)

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Low Energy: With HM-10 bluetooth 4.0 module, you can add Bluetooth features to your project and support iphone4s or later.
DSD TECH Brand 4pin Base Board: Through this base board, leads to VCC, GND, TX, RX. You can be very convenient to connect to your arduino project