The Ejector is a RedPower machine. It can function just like a Chest and a Transposer in one. It can store items as well as push single items into Pneumatic Tubes.
Recipe[]
Recognition From Other Mods[]
It is recognized as a chest by other mods, therefore it can receive items from BuildCraft Pipes. However, it cannot actually push items into a BuildCraft pipe. Thus it can serve as a possible link between BuildCraft Pipes and RedPower Pneumatic Tubes.
Alternatives[]
A Relay or Filter could be considered a better alternative to this with considerably more functionality.
Powering[]
When presented with a redstone pulse, it will eject a single item. It is also capable of ejecting directly into inventories and other chests. This includes Industrial Craft machines.