Features:
Can easily achieve serial wireless data transmission.
The operating frequency is among the most popular 2.4GHz ISM frequency band.
Adopts Bluetooth 2.1+EDR standard.
Super easy to make it work and makes wireless Serial comms to any project a breeze.
The workload of bluetooth chip can be reduced substantially and more sleeping time can be saved for bluetooth.

Specifications:
Brand: Keyestudio
Model: Bluetooth Module
Material：FR4
Color: Black + Yellow
Bluetooth Protocol: Bluetooth 2.1+ EDR Standard
USB Protocol: USB v1.1/2.0
Operating Frequency: 2.4GHz ISM Frequency Band
Modulation Mode: Gauss frequency Shift Keying
Transmit Power: ≤ 4dBm, Second Stage
Sensitivity: ≤-84dBm at 0.1% Bit Error Rate
Transmission Speed: 2.1Mbps(Max)/160 kbps(Asynchronous)； 1Mbps/1Mbps(Synchronous)
Safety Feature: Authentication and Encryption
Supported Configuration: Bluetooth Serial Port (major and minor)
Supply Voltage: +3.3 VDC 
Working Current: 50mA
Operating Temperature: -20 ～ 55℃ / -4 ～ 131℉
Item Size: 4.2 * 1.6 * 0.8cm / 1.6 * 0.6 * 0.3in
Package Size: 6 * 2.5 * 1cm / 2.4 * 1.0 * 0.4in
Package Weight: Approx. 5g / 0.18oz 

Package List:
1 * Bluetooth Module