Flusher is a tool designed for wood framers. It’s an add on for the hammer and it can be used to make two studs flush.
It’s small enough to stay in the framer’s pouch until he needs it. Once he sticks it to the head of the hammer and he hits the stud, the big pin goes inside the wood and it works as a nail. Prying the flusher enables two pieces of wood to be aligned until being shot by a framing nailer.