The Disco Ball is one of the sandbox-exclusive gadgets introduced in the 10.1.0 update.
Much like the Jukebox, it looks like a grey turret from the base with speakers on the sides, with a black, spinning disco ball with multiple bright colors which are red, blue, green, yellow, cyan and magenta. Each side has a square-shaped center with a green light in the center of each center.
The Disco Ball acts like a Turret. It can be deployed anywhere on the map. When a player gets close to it, disco-like music will emit out of it.
It seems the bottom and the rotary ring of this gear is from the Turret's model.
The disco ball is not entirely solid. If one jumps onto the disco ball, that player would quickly come to notice that he is standing on top of the brown box instead of the ball.
Players can stack these on top of each other if other players deployed one.
It is possible to trap players with it, by making them go to the small cabin in Quiet Island, then having a Disco Ball deployed at its entrance.