LDream Bluetooth CSR 4.1 Receiver Adapter 3.5mm Output for Car & Home Audio System Enable Siri: for a better iOS user experience, add the Siri function to this bluetooth receiver, activate the voice software by long press the muti-function button Handsfree: provide a simple hands-free solution for answering and receiving phone calls and streaming music from your bluetooth-enabled tablets and phones while on the go Two-link: can connect two bluetooth devices at the same time. Over length receiving distance, can reach up to 30 feet in open space without cables. Bluetooth version: adopt bluetooth V4.1+EDR technology with superior wireless performance Sleep mode: enables energy conservation when not use