This propeller adapter makes it easy to attach a propeller or other device to the MTR-2000 Underwater Motor.  It fits over the 8-mm shaft and is secured with an M4 set screw.
 
The adapter's outer diameter is 10 mm and the threaded portion is M10 x 1.25.  The propeller adapter, set screw, and nut are made of 316 stainless steel.
 
M10 x 1.25 nut and M4 set screw included.