This is the 5/16"-24 Adapter for the ElectriFly Aluminum E-Spinner. / / FEATURES: Adapter for use with 5/16"-24 Prop Shafts / Aluminum Adapter / / INCLUDES: One 5/16"-24 Spinner Adapter / One 30mm Socket Head Screw / One 25mm Socket Head Screw / One 20mm Socket Head Screw / One 13.5mm Socket Head Screw / / REQUIRES: Use with ElectriFly Aluminum E-Spinners: / 1.5" (GPMQ4703) / 1.75" (GPMQ4711) / 2" (GPMQ4719)