This is a freshly-reworked Acme 536 propeller that was used on an Air Nautique.
Manufacturer Part Number: 536
# of Blades: 4
Diameter: 13.5"
Pitch: 16"
Shaft: 1-1/8"
Right Cup: .105"
 
The ACME 536 4-Blade 13.5" x 16" Propeller is a revolutionary prop for wakeboard boats and is an excellent option for those that enjoy wakeboarding and wakesurfing.
 
The ACME 536 4-Blade 13.5" x 16" Propeller offers more surface area which means a more efficient transmission of power, higher fuel economy, and more consistent speeds. Thanks to ACME's continued devotion to push the ski and wakeboard boat propeller industry to new heights inboard props are helping ski and wakeboard boats achieve performances never before seen.
 
Prior to 1999, ski and wakeboard boat propellers were cast from molds, a process that offered little precision and had severe limitations for the size and shape of the blades. The result was inefficient props with small blade surface area and poor balance which caused vibration in the boat drive train. However, all that changed when ACME introduced CNC machining to the inboard propeller industry. By precision machining its waterski and wakeboard boat propellers ACME is now able to hold tolerances and achieve accuracies never before seen in the inboard propeller industry.
 
What does that mean for you? The ACME 536 4-Blade Propeller will perform up to and surpass the standards you expect from the moment you pull it out of the box and put it on your boat.