ON/OFF Conveyor Belt
From the Super Mario Wiki, the Mario encyclopedia
New Super Mario Bros. 2
In New Super Mario Bros. 2, ON/OFF Conveyor Belts are exclusively found in World Flower-, where only three of them appear: two lead to the area with the third Star Coin, while the other is the setting for the boss fight with Lemmy. They are controlled by pressing yellow switches near them.
Super Mario Maker 2
In Super Mario Maker 2, ON/OFF Conveyor Belts are course elements that function as regular Conveyor Belts that can have their direction switched by hitting an ON/OFF Switch. The game still refers to them as Conveyor Belts.