This is a Nintendo Switch Joycon Grip Holder. This is designed to hold two standard or charging Joycon Grips with the Joycons on them.

I had my original Joycon Grip always laying around while the Joycons were on my Switch. I also had a charging grip and an extra set of Joycons that found themselves on desks or floors more often than not. This stand just gives me a place to put the grips when I'm not using them.

The stand pictured is my custom version that doesn't let you place the upper grip in with joycons attached. This is so I can't be lazy and not hook the Joycons to my Switch to recharge them when I am done. The actual model will let you be lazy.