Available in 17- and 20-inch diameters and 7, 8, and 9 inch widths. Strong steel construction from cold rolled steel and satin black coated. Bolt patterns of dual 5-lug (5x4-1/2/5x4-3/4 and 5x5/5x5-1/2) or 6-lug (6x5-1/2) Uses standard 60-degree conical lug nuts (not included) Center bore of 3-1/4 to 4-1/4-inch (varies by wheel size) fits over most axle flanges and brake hubs. 4" Wheel backspacing. Chrome plated “baby moon” center cap included. Utilizes push-in or bolt-in valve stems (sold separately) Give Your Ride the Timeless Look of Smoothie Wheels with Modern Rubber The true meaning of hot rodding post WWII was all about doing more with less and finding usable parts in the junkyard from other models. In the 1940s and 1950s there wasn't the huge aftermarket support there is now for wheel styles. It would be another decade before American Racing's aluminum wheels would hit the market. One of the first “custom” wheel styles was called the reverse wheel. This was simply a standard passenger car vented steel wheel with the center cut out, reversed, and welded back into the rim to provide a deep dish look. These were often chrome plated or painted to match the car with a trim ring and chrome lug nuts used to dress up the painted version. Sometime in the 1970s the advent of the “smoothie” wheel surfaced. This was still a steel wheel, which kept costs low, but the center stamping no longer had any sort of venting slots or openings. The smooth look was often accompanied by a trim ring of some sort and a lug nut cap. This lug nut cap was often referred to as a “dog dish” cap due to its outward appearance as a dog dish when removed. Many also referred to the smooth lug nut cap as a “baby moon” cap, named so after the appearance of the full moon wheel covers made popular in land speed racing and made famous by Dean Moon's shop as Moon discs