Item Type: Passive Radiator Material: Plastic Product Size: Approx. 92x92x22mm / 3.6x3.6x0.9in Distance Between Adjacent Screw Holes: Approx. 61mm / 2.4in Diagonal Screw Hole Distance: Approx. 85mm / 3.3in Package List 2 x Passive Radiator 8 x Nail Please allow 01mm / 00.04in error due to manual measurement. Thanks for your understanding. 1HIGH QUALITY PLASTIC: This woofer diaphragm is made of high quality plastic material, which is durable. 2BASS DIAPHRAGM: Enhance the bass effect of the speaker and eliminate the disturbance of the airflow of the cabinet. 3FULL RANGE SPEAKER: This DIY subwoofer has a full range speaker bass enhancement effect. 4THE MAIN FUNCTION: The main function of this speaker diaphragm is the speaker, woofer, and bass vibration. 5PRODUCT SIZE: The product size is Approx. 92x92x22mm / 3.6x3.6x0.9in, the distance between adjacent screw holes is 61mm / 2.4in, and the distance between diagonal screw holes is 85mm / 3.4in.