Actually, its not that its too complicated. The prop shaft on the Moki is too short and because of that you have to have a special adapter to mount any kind of spinner. Right now I have a Tru-Turn backplate mounted on my engine, a Zinger 18x10 wood prop, the prop washer that came with the engine, and the prop nut that came with the engine (BTW the prop nut recesses into the prop washer) and I have ZERO more threads on my shaft, i.e., the front of the prop nut is flush with the front of the shaft. The only way I'm going to be able to attach the spinner is with a special adapter that replaces the prop nut. Like the original prop nut it will have to recess into the prop washer to get enough threads to tighten. Moses' picture shows an adapter that goes one step further by recessing all the way through the prop. That gives me more of a warm fuzzy the prop won't fly off the 1st time my engine starts backwards. And, it does happen -- I discontinued my break in sessions until I get my Tru Turn adapter because I've already thrown the prop with my setup. Lucky for me I did not loose the prop washer and prop nut. You should have heard that engine scream with no prop load at full throttle -- luckilly it was running max rich.