Downward Double Piston Extender, it works but I don't understand why. Any explanation? - Redstone Discussion and Mechanisms - Minecraft: Java Edition - Minecraft Forum - Minecraft Forum
Tile-able Double Piston Extender/Retracter - Redstone Discussion and Mechanisms - Minecraft: Java Edition - Minecraft Forum - Minecraft Forum
Redstone Tutorial: The Double Piston Extender Minecraft Blog | Minecraft designs, Minecraft houses, Minecraft tutorial