Steam is input to the bottom face of the block. It has an internal storage of 10,000 steam. It will launch entities within 5 blocks in front of it back and into the air, consuming 500 steam. It has a 300 tick cooldown period, so even if its steam storage is immediately replenished, it will take 300 ticks until it propels another entity.
Right clicking on the lock will display a message in chat stating how much steam is currently stored within the Blowback Cannon.
It cannot currently be crafted.