Eisco Labs Optical Glass Lens, Double Concave, 75mm Diameter, 20cm Focal Length

EISCO Optical Glass Lens, 3" (75mm) - 200mm Focal Length - Ground, Beveled Edges - Use as Top Spinning Base

ForeverSpin Titanium Spinning Top - World Famous Spinning Tops

DjuiinoStar 4" Spinning Top Base (Rounded by Silicone), 30cm Focal Length (Double Concave), 100mm Large Gyroscope Station (Help to Prolong Your Average Spinning Time) DSTB-1005