If you have multiple Switch controllers, this is a handy gadget to charge them all at the same time. It can work with 2 professional controllers and 4 half joysticks at the same time. By leaving a row of joycons connected to the Switch, you can charge up to 5 full controllers at once. It should be noted that the joystick charging slots require strong pressure on the joystick to make contact. At first I thought the problem was with this slot. I finally found that everything works great if you press the joystick down firmly until you hear a faint click.