Features: Adjustable notch filter, 6.5inch full frequency speaker dedicated HiFi sound blocker filter. The temperature resistant inductors and ferrite magnetic circlet with better sound quality. Fever level 6.8μF+4.7μF (adjustable) specific capacitor, enjoy HiFi sound quality. The notch filter and reduction amount can be adjusted through the sound quality adjustment switching button to freely adjust the desired sound quality. Four position solderless terminals block, without need for soldering, convenient and simple, easy connection. Specifications: Material: Metal Size: approx. 47x58x24mm/1.85x2.28x0.94inch Capacity: 6.8μF+4.7μF (adjustable) Applicable impedance: 4-8Ω Applicable speakers: Full frequency speakers under 6.5 inches Package Includes: 1Pc Adjustable Notch Filter note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.