Features: Double channel design: specifically designed for double channel sound amplifiers to enhancing output. with Components: As accessory that includes all components, it is perfect for customizing sound projects. Independently power supply: Operating at AC12-15V, an independently power supply is required to protect the loudspeaker. Startup delay and direct current protections: With startup delay (3 seconds) and direct current protections (1V) functions, it can achieve safe operate. High current relays: equipped with 15A high current relays, suitable for most amplifier boards. Specifications: Component: circuit board Size: 6.5x4cm/2.56x1.57inch, standard size, suitable for most loudspeaker equipment Attribute: double relays design, providing safety and stability Technical parameters: Equipped with power-on delay function to effectively prevent current shock | direct current protections mechanism to ensuring equipment safety Usage scenarios: Home sound device| Professional sound equipment | Portable loudspeakers Package Includes: 1Pc loudspeaker Protective Board note: After receiving, you may need to assemble yourself. Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.