Color Red Brand SoaringE Model E00306 Quantity 1 Piece Material FR4 English Manual / Spec No Other Features As we know TX and RX are LVTTL meaning 3.3V signals. But this module can directly connect to 5V TTL signals (take Arduino for example) without any problems and you don't need to worry any damages it will never happen it is therefore highly recommended to use transistors to interface with a 5V TTL signal. Specification Bluetooth protocol: Bluetooth Specification v2.1 + EDR USB protocol: USB v1.1/2.0 Frequency: 2.4GHz ISM band Modulation: GFSK (Gaussian Frequency Shift Keying) Transmit power: 4dBm Class 2 Sensitivity: -84dBm at 0.1% BER Rate: 2.1Mbps(Max)/160 kbps(Asynchronous);1Mbps/1Mbps(Synchronous) security features: Authentication and encryption Support profiles: Bluetooth serial port (master & slave) Power Supply: +3.3 VDC 50mA Operating temperature: -20 ~ +55 Centigrade Features Support Bluetooth standard v2.1 + EDR. Supports soft/hardware for master/slave mode setting. Through the AT command yon can set the control parameters of the module and issue orders to the module. Working state instructions. Suitable for embedded serial transmission wireless alternative. On-board efficient antenna. Support connecting seven slave equipment. Packing List 1 x TTL Serial Bluetooth module Bluetooth Bee master