Specification: Frame Material: ABS Plastic Mesh Material: Cold Rolled Steel Outer Diameter: 185mm /7.28inch Inner Diameter: 146mm / 5.75 inch Screw Hole Diameter: 4mm / 0.16 inch Diagonal Center Hole Distance: 167mm / 6.57 inch Package Content: 4pcs x Speaker Grill with Screws Description: Distribute screws, make you more convenient installation. Great for speaker cabinet, home speaker or speaker. Protect your Subwoofer from cuts, rips, tears and dents. Note:6.5 inches is the product's mounting size not for 6.5" speakers.