It doesn't get much rarer than this. 

I don't think they made many of these.   

I don't know how this propeller survived 100 years.

This propeller is off of the communication radio set from a Curtiss NC Flying Boat from 1918-1919.  * We do not have the radio set, just the propeller *

Propeller measures 24 inches long x 3 inches tall x 6 1/4 inches wide (hub diameter)  Weighs just under 2 lbs.

USN (United States Navy) Stamped on back of hub (see photos)

Type CQ-1265  (CQ stands for International Radio Telegraph Co)

Original decal (see photos)

Awesome original patina (see photos)

In May of 1919 the US Navy sent NC-1, NC-2, NC-3 and NC-4 on their way to the first transatlantic flight.  There were many issues along the way and the NC-4 was the only one that made the flight across the Atlantic. ()

The US Navy's Curtiss NC-4 was the first airplane to achieve the transatlantic flight.

The US Navy wanted the best of the best equipment in these planes and wanted the communication systems to be to top notch. They wanted the planes to be able to communicate with land and sea bases as well as communicate between each other.

The communication radio system was a combined effort by the International Radio Telegraph Company (CQ) and the famous Lang Airplane Propeller Company ().  International Radio Telegraph Company (CQ) was only around from 1918-1920 () 

There is a ton of detailed information on this radio equipment.

(Aircraft Journal - May 31st, 1919)

(Aerial Age Weekly - Oct 27- Nov 3, 1919)

(Telegraph and Telephone Age - June 1, 1919)