Review on 🎧 Cmple - [10 Pack] 3.5mm Mono Male to 2X 3.5mm Mono Female Coupler Adapter, Audio Jack for Headphones by Dawn Kraft

If you're lucky enough to find one that works, you'll first notice that it sums the stereo signal to mono, and that's after you shake it up right so you don't just hear one track. Some of them are tight or impossible to connect, others are so loose that they don't provide a reliable connection. You can't trust them to even play summed mono without checking the headphones, making them null and void in a complex patch. At least half ends up in the trash because they don't work at all. What mistake.