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
The Worlds SMALLEST Double Piston Extenders (Minecraft 1.13+) - YouTube
Help make FLUSH 2 high double piston extender - Redstone Discussion and Mechanisms - Minecraft: Java Edition - Minecraft Forum - Minecraft Forum
MC-159945] Permanently powered piston with no redstone input (not pushing redstone block) - Jira
Fast and simple double piston extender for moving Mobs/Players! : r/redstone