Features: 2 Pieces 4021 circle full-range audio speaker stereo woofer loudspeaker. 4Ω impedance 3W power. 99-10000 kHz frequency response, omnidirectional directivity. Made of high-quality metal materials, exquisite workmanship, and long service life. Wired DIY audio accessories, applicable for notebook computer laptop etc electronic equipment modification. Specifications: Type: Electric type (moving coil type) Application: Hi-Fi (home use) Shape: round Composition: coaxial composite Diaphragm Material: paper Magnetic Circuit Form: internal magnetic type Frequency Characteristics: full frequency band (full sound range) Rated Power: 3 for W Rated Impedance: 4 Ω Frequency Response: 99-10000 kHz Directivity: omnidirectional Sensitivity: 89dB/for W Signal-to-noise ratio: 87 dB Harmonic Distortion: 3TMD% Material: Metal Diameter: Approx. 40 mm/1.57 inch Quantity: 2Pcs Package Includes: 2 Pieces 4 Ω 3W Speakers note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.