|Source Mod||RedPower 2|
The Buffer Gate is one of numerous blocks added by RedPower 2 which allows for far more compact Redstone circuitry. When the Buffer Gate is receiving power from its input face (the face with the wire running towards the shortest Redstone torch) then the output faces (the remaining three faces) will output a Redstone signal. This makes the Buffer Gate a sort of inverted AND Gate, as the AND Gate outputs a Redstone signal from one face if the other three are receiving power.
The Buffer Gate has a short delay between when it receives a Redstone signal and when it outputs a signal, similar to the vanilla Redstone Repeater. Likewise, it also renews the signal strength of the Redstone current and does so on three separate sides. This could be useful for splitting a signal into three different parts easily to send the same signal to more than one location.