Built between 1975 and 1977 this airboat propeller is wood with brass ends. The Sensenich logo seal is very clear and over all the propeller is in very good condition. There is an impression in the bolt area where it has been attached to an airboat. The serial number is 78 LXL 56 and under that is Z 537. In a call to the company I found out it was an airboat propeller and that the 78 was the length of the blade and 56 was the pitch.