In the first row, there should be 3 cobblestones. In the second row, there should be 1 cobblestone in the first box and 1 cobblestone in the third box. In the third row, there should be 1 cobblestone in the first box, 1 redstone in the second box, and 1 cobblestone in the third box. This is the Minecraft crafting recipe for a dropper.
The slot is chosen when an item is ejected, not when the dropper is initially activated, thus it is possible to move items into or out of a dropper between its activation and item dispensing. If the dropper is facing a container, the ejected item is transferred into the container.
A dropper pipe must be clocked to move items, but can be clocked to move items faster than a hopper pipe's transfer rate. When a dropper pipe pushes items upward, it is known as a droppervator (short for "dropper elevator"). Droppers can be placed under note blocks to produce "bass drum" sounds.
A dropper can be mined with a pickaxe, in which case it drops itself and its contents. If mined without a pickaxe, the dropper drops only its contents. ↑ Times are for unenchanted tools as wielded by players with no status effects, measured in seconds. For more information, see Breaking § Speed.