Gon Bops California Series Quinto, 10.75-inch, 55th Anniversary Edition Contour Crown Hoop features unique design with traditional looks and easy-play functionality Steel Side Plate made from heavy-gauge steel and fixed using steel carriage bolts and steel backing plates The highest grade quarter-sawn North American Red oak is used for each and every hand-cut stave Custom-made bottom rings are individually fitted to each Conga by Artisans who hammer each ring into place, providing additional strength