William F. Breitenbaugh of Philadelphia, PA, received a 1915 US Patent that covered this mechanical marvel  The club could be used as an iron with varying degrees of loft, as selected by the golfer, as well as a putter. 

This club operates using a nut on a threaded blade stem that extends through a forked hosel. To operate the blade you rotate the nut.  Rotating the nut in one direction moves the blade away from the hosel so it can be adjusted to the desired loft; rotating the nut in the opposite direction draws the blade tight to the hosel and locks it in place. 

Both sides of the blade are scored and designed to strike the ball. Consequently, both right-and left-handed golfers could use either side of the blade, could use the blade either right-side-up or upside-down. This featured allowed any golfer to select from two blade shapes depending on the type of sole desired—either cured or flat. 

This club is marked "The Master club / Pat'd Apr 27, 1915" on one face.  The 39" shaft and leather wrap grip are original.  These are few and far between, and this is a great example, cleanly marked and all original.