ITEM NAME:BT-12 Bluetooth Dual-mode Serial Port BLE4.0+2.0 Replace HC-05 2541 Mod IFV HCI Descriptio n Specification:.BT12 Bluetooth Dual Mode Serial Port Transparent BLE4.0+2.0. Purpose: bluetooth dual - mode module. Features: bluetooth dual mode module. Product list :1pcs BT12 bluetooth dual-mode module. Modulation mode: GFSK(Gaussian Frequency Shift Keying).