Features:--4-Channel 9900 Watt Car Power Amplifier--Amplifier Class: Class A/B--Stereo surround--Main push four-door speaker--Passive subwoofer--Slim design--Aluminium alloy casting drawing process--External heat sink--Thermal Overload Speaker's Short Protection--Shell with a ...Features:--4-Channel 9900 Watt Car Power Amplifier--Amplifier Class: Class A/B--Stereo surround--Main push four-door speaker--Passive subwoofer--Slim design--Aluminium alloy casting drawing process--External heat sink--Thermal Overload Speaker's Short Protection--Shell with a standard safety interface put and end to bad parts--Aluminum alloy heat disspation design hole design wider air-contact surface heat faster - Specifications:Model: SK-990.4Material: Aluminium alloy - Channel: 4Working Voltage:DC 12VPeak Power Output: 9900 WPeak Power Output: 2 Ohms 2400Wx 4 Channels - Peak Bridged Power Output: 4Ω 4900W x 2 Channels - RMS Power Output: 4Ω 120W x 4 Channels - Total Harmonic Distortion (THD) RMS Output: <0.01%Signal-to-Noise Ratio (SNR): >95d - BSensitivity: 150m - VImpedance: 2Ω~4ΩFrequency: 20Hz~40KHz - Package Include:1 x Power amplifier - Notes:1. Due to manual measurement, please allow a difference of 0.5-1cm.2. Due to the difference of light and screen, the color of the product may be slightly differe