Suitable for speakers: no more than 2 inches high pitch , no more than 4 inches of mid-range The central hole is divided into two sections. Install a 4-inch midrange speaker, then remove the washer to install a 100mm diameter 4-inch midrange speaker. Install a 3-inch 3.5-inch midrange and use the washer on the pad. (If you install a 3.5-inch midrange speaker to install the aperture and speaker cover, you need to pay attention to the car a column is than 111mm). Tweeter Outer Diameter: 58mm Tweeter Internal Diameter: 47mm Mid-range External Diameter: 102mm Mid-range Internal Diameter: 85mm Maximum width of the bracket: 111mm Bracket length: 270mm color: White material: plastic Package Contents: 4*Speaker bracket Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.