Great Planes Electrifly E-Spinner 2" with Aluminum Backplate, Transparent Black Great upgrade for Great Planes E-Performance series ARFs. Features a lightweight aluminum backplate with stepped adapter hole for easier, more accurate reaming. Drilled for 1/4" (6mm) shaft with drill guides for 5/16" (8mm) shaft. Includes: Spinner(1), Backplate (1), Phillips Head Screws (2), Instructions.