ITEM NAME:5Pcs TRRS 3.5mm Jack Breakout Board Headset Stereo Socket Extension Module TRRS connectors are the audio-style connectors that you see on some phones, MP3 players and development boards. TRRS stands for “Tip, Ring, Ring, Sleeve,†which reflects the fact that, unlike a standard stereo connector, this actually has three conductors and a ground. Some devices use the extra conductor for a microphone (like hands-free headsets) or to carry a video signal (like in some MP3/MP4 players). Description: Mini design, portable and easy to use This breakout board makes it easy to add a TRRS jack to your prototype or project by breaking out each conductor to a standard 0.1" spaced header. Lead to the left channel, right channel, ground wire, and the lines of the plug Size: Approx 1.7*1.2cm / 0.6*0.5 inch Material: Plastic + metal Package Includes: 5 x Breakout board 5x Pins Header.TRRS stands for “Tip, Ring, Ring, Sleeve,†which reflects the fact that, unlike a standard stereo connector, this actually has three conductors and a ground. This breakout board makes it easy to add a TRRS jack to your prototype or project by breaking out each conductor to a standard 0.1" spaced header.