Description: brand new and high quality Features: It is used to replace the inverted tube. Made of high-quality material, durable and stable to use. A passive radiator is used to adjust the , the designer can adjust the overall tone of the speaker. The radiators have great effect on enhancing the , booster, convenient debugging. Each speaker behind with a diaphragm right unit,can increase the lower potential of the , the sound more excellent. Attention: it is passive radiator,not speaker.No voice coil or drive magnet. Passive Radiator only, other accessories demo in the picture is not included! Specifications: Item Type: Passive Radiator Material: Plastic+Metal Size: (Optional) 4 inch: horn diameter: 116mm/4.5in, diagonal twisting hole spacing: 108mm/4.2in, opening hole: 95mm/3.7in, counterbore depth+height: 2.5mm+33mm/0.09+1.2in 5 inch: horn diameter: 147mm/5.7in, diagonal twisting hole spacing: 139mm/5.4in, opening hole: 118mm/4.6in, counterbore depth+height: 3.8mm+37mm/0.14+1.4in 6.5 inch: horn diameter: 178mm/7in, diagonal twisting hole spacing: 168mm/6.6in, opening hole: 145mm/5.7in, counterbore depth+height: 4mm+47mm/0.15+1.8in Color: Black Quantity: 2 PCS Note: No retail package. Transition: 1cm=10mm=0.39inch Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Includes: 2 x Passive Radiator