StarTech.com 4 Position to 2x 3 Position 3.5mm Headset Splitter Adapter - Headset splitter - 4-pole mini jack male to mini jack female - 20 cm - black - for P/N: DK30A2DH, DK30CHDDPPD, DK30CHDPPDUE, MST30C2HDPPD, USB3SMDOCK4K, USB3VDOCKD