Specification: Frame Material: ABS Plastic Mesh Material: Cold Rolled Steel Outer Diameter: 139mm / 5.47 inch Inner Diameter: 93mm / 3.66 inch Screw Hole Diameter: 4mm / 0.16 inch Diagonal Center Hole Distance: 108mm / 4.25 inch Package Content: 2pcs 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.