Model:ELF13 TitiniumUse: Monitoring Headphone Accessories Construction: Coaxial composite ?Magnetic circuit form: Internal magnetic formula ?Type: full rangeSize:50MM ?Rated power: 0.05 W ?Impedance: 32 ohm ?Frequency: 20-20KHZ ?Sensitivity: 110dB/W ?SNR: 96dB ?Distortion: 1 TMD Percent ?Directivity: the marked color point is the unit positive pole Speaker timbre: smooth curve, high comprehensive quality, suitable for monitoring, noise reduction, HIFI earphone, low resistance and easy to push, high three-frequency separation. Packaging: ? ?2x Headphone Speaker unit Instructions: ? ?Please test the speakers with a multimeter before soldering. ?The colored spot is for positive pole +, the other side is for negative -. ?Soldering with less than 3 seconds. Otherwise, the voice coil or circuit board can be burned out easily.Note:All ELFINEAR Driver units have /curve/ distortion/phase/the DB value/voice frequency sweep pairing/ tested and confirmed before shipping. After receiving the drivers, please check the package and test its qualtiy by using a multimeter or other devices before welding, due to the unit belongs to the perishable goods, are not provided after welding.