The 1010music line of stereo breakout cables are designed to connect 2 mono audio signals to a single stereo TRS 3.5 mm minijack plug. The slim plug caps fit side by side with other cables in compactly spaced input jacks, like those on the 1010music bluebox. These cables may have been designed for the bluebox, but they have a wide variety of uses with other gear as well.
Each of these cables has a male TRS stereo 3.5mm minijack plug on one end and two female TS mono 3.5 mm minijack plugs on the other end. They are 15 cm/6 in long with the 1010music logo printed on the plug caps. Available individually and in 3 packs.
Info from 1010music