If you set this thing on top of a hill, it'll scare your attackers away! The arrows actually catch fire due to lava, and it fires five times per second!
This takes advantage of another superfast pulser that turns ON or OFF from the same button!
The one disadvantage is that it doesn't fire very far, that's why you should put it somewhere high up.
Because it fires so fast, it'll run out of arrows quickly as well, so be prepared for an empty barrel!