Reactor Button is the smallest block of the reactor-room set in Ala Industrial and the only one without which the room becomes a trap. The airlock door opens on a redstone pulse (a short signal) alone: outside, anything can send one, but a sealed room has no openings or wires leading out, so the pulse source has to stand inside. Reactor Button is made of the same shielding alloy as the walls and works like a real vanilla button: press by hand, the model sinks in, the pulse fires and auto-releases. The press lasts 20 ticks (1 second) — as long as a stone button's, and exactly half the door's 40-tick cycle, long enough for the door to catch the rising edge even through a trail of redstone dust.

One Shielding Plate plus one stone button crafts two Reactor Buttons on any crafting grid — a shapeless recipe that dresses a familiar vanilla button in shielding alloy. Inside the room, hang Reactor Button on the casing next to the doorway: the button attaches to walls, floors and ceilings, spends no shell cell, and the seal stays whole. An arrow cannot press Reactor Button, so a stray skeleton shot never opens the airlock. Reactor Button runs on redstone alone with a 0 EU buffer, so the exit control keeps working during a power outage. Hardness 0.5 and blast resistance 0.5 are deliberate: Reactor Button is not meant to outlive the wall it hangs on. The mod runs in Minecraft 26.2 Java Edition on Fabric and NeoForge.