Product Name: HD-105 4'' Different Sizes Column Loudspeaker Model NO.: HD-105 THD: <0.005% Monitor: Lcr Certification: CE Application: Commercial, Home Speaker Material: metal Speaker System: Optional Combination Operation Mode: Wire / Remote Control Activity: Passive Hi-Fi: Not Hi-Fi Noise: <95dB Trademark: feilep Transport Package: Carton Specification: 152x340mm Origin: China Product Description power(RMS)20W/30W/40W/60WLine Voltage70-100v ACFrequency200-10000KHz/90HZ-16000HZSensitivity90dBSpeaker Unit4''X2/4''X3/4''X4/4''X5Overall Dimensions152x340mm/152X450MM/152X580MM/152*710MMShell MaterialMental100 VOLT TRANSFORMER: FEILEP ceiling speakers feature 100 volt transformer, while an 8 ohm bypass setting allows use with regular home audio receivers and amps. The product is made to produce powerful, rich sound or quiet background music200Hz - 10000kHz FREQUENCY RESPONSE: FEILEP 4" speaker system This flush mount speaker is pack with exceptional 8 ohm impedance rating and impressive 100 watts power handling capability.100 WATTS PEAK: FEILEPin-wall speaker system were carefully combined to reproduce sound clearly with outstanding responsiveness. It has 90 dB that can achieve wide-ranged sound performance speakers secure as well as extending the life of the productEASY INSTALLATION: The product includes overall cut-out template for easy installation The product also includes the mounting hardware for installation for precise application4-inch speaker woofer system, different size contain different quantity of speakers for your choices.