An extension of the body, the machine enhances rearward communication for the wearer with minimal effort.  The user clamps the mechanism onto their forearm (either one) and inserts a finger (middle or index) into the trigger ring.  When the time is right, a quick tug at the trigger ring will launch the wooden digit in a one-fingered salute to whoever is behind.  Ideally suited to urban cyclists, the Wooden Finger Machine is constructed from workshop scrap materials, and relatively cheap to produce.