THIS IS FOR (QTY 2) MDF 10 INCH SPEAKER RING INSIDE DIAMETER --- 9 INCHES OUTSIDE DIAMETER ---- 11 INCHES THICKNESS -- 3/4 ALL RINGS ARE MACHINED FOR PERFECT ACCURACY PLEASE CONTACT US FOR CUSTOM CUT RINGS & SIZES WE HAVE MULTIPLE MDF RING SIZES & STYLES THESE ARE GREAT FOR BUILDING FIBERGLASS BOXES, CUSTOM SPACERS