... A2DP, AVRCP, OPP, DUN, SPP profiles 2.Class 2 3.UART&USB 4.Small Size MDCS56 Class 2 Bluetooth Headphone ModuleIt is a improved model in ... audio signal control base on MDCS51 bluetooth ... Features:. Bluetooth v2.1+EDR, Class 2. Profiles including HS/HF, A2DP, AVRCP, OPP, DUN, SPP, and etc.. UART and USB programming ...