This is the H2X Shaft Pin with SKU number X400130 and is one element that goes with the Blade Prop Kit. The H2X Shaft pin is a prop shaft pin and is a component of the wave propulsion.
The 1/4-20 Threaded Insert for Wood from Master Spa Parts are threaded nuts that can be hammered or screwed into material. Used in a pre-drilled hole to provide an extra secure hold between your spa skirting parts.