To connect to an Android platform in Open Accessory Mode, the platform must first support the mode. This is true of OS version 3.1 onwards, but may also be available on OS versions as far back as 2.3.4 if the user has back ported the feature to this OS version. When an Open Accessory device is connected to the Android, it must send a vendor request to the Android to inquire if the device supports Open Accessory Mode. This is the Get_Protocol command. The communication stops there if the reply is no. If the reply is yes, the peripheral sends its own unique descriptor strings to identify itself. There is then another USB vendor request to enable the Open Accessory Mode and re-enumerate the Android device in this configuration. When enumerated as an Open Accessory Mode device, there will be one USB BULK IN endpoint and one USB BULK OUT endpoint as well as the control endpoint. This interface will be full speed (12Mbit/s) USB allowing for data transfer in and out.