This Great Planes' 1-Piece Yellow Nylon Spinner with Aluminum Backplate.
Yellow nylon 2-blade spinner. Aluminum backplate. A sturdy aluminum backplate holds the spinner in round, which means it turns truer, with less vibration. The engine shaft hole is stepped from 5/16 in. to ¼ in., to perfectly center the opening if enlarging is needed.
Spinners attach securely to backplates with the included screws.
Diameter : 3 in. (76mm)
Backplate Thickness : 1/8 in. (3mm)
Shaft Size : ¼" (6mm)