WD® Plastic Humbucker Pickup Mounting Ring These mounting rings are made for either flat top or arched top guitars in the most commonly used colors.Flat Set:This is a typical set of plastic mounting rings found on most 2 humbucker guitars. It is comprised of 1 high and 1 low ring.High Flat:This tall plastic humbucker mounting ring is generally used in the bridge position on a two or three pickup guitar. This mounting ring is angled in height so the side closest to bridge is taller than the side closest to the neck or fretboard.High Arched:This is a tall plastic humbucker ring with an arched radius, designed for usage in the bridge position arched or carved top guitars. This mounting ring is not an exact Gibson® spec replacement ring. It has slightly larger exterior dimensions with an overall (top and bottom) arched design and slightly different mounting hole locations.Low Flat:This is the shortest plastic humbucker mounting ring we stock and is generally used in the neck position. This is angled in height so side closest to bridge is taller than the side closest to the neck or fretboard.Low Arched:This is a short plastic humbucker ring with an arched raduis, designed for usage in the neck position arched or carved top guitars. This mounting ring is not an exact Gibson® spec replacement ring. It has slightly larger exterior dimensions with an overall (top and bottom) arched design and slightly different mounting hole locations.Medium Flat:This medium plastic humbucker mounting ring is generally used in the middle position on a three pickup guitar. Also can be used in neck or bridge position depending on height requirements of your instrument. This is angled in height so side closest to bridge is taller than the side closest to the neck or fretboard.