Lossless transmission for 8 pin to 3.5 headphone socket wiring 1: for iphone 8 pin adopts stretching seamless shell technology, with gold-plated terminal and nickel-plated shell, and its interface meets the requirements of the association. 2: DC Jack is in line with 3.5mm 4 pole bus socket for connecting DC wired earphones. Note: after first time to connect with your for iphone bluetooth , then no need connect again for next use Note: Volume(+-) can not work thru this adapter cable