you can make one with a piece of 4 inch pvc pipe.<br />just cap one end and use one of those rubber sewer pipe splices (like the ones for conecting PVC pipe to old cast iron pipe) a few 1/2 inch holes in the pipe. one end of the rubber sleeve simply slides over your prop hub and tightens with the band clamp. total cost is about <br />$12.00. I will try to take a picture this weekend. all the parts are available at your local lumber yard.<br />here is a link to the coupling<br /> http://www.brandnametools.biz/plumbing/p/Pipe_Couplings/_1273400.htm