Pyle Hydra Marine Amplifier - Upgraded Elite Series 400 Watt 4 Channel Micro Amplifier - Waterproof, GAIN Level Controls, RCA Stereo Input, 3.5mm Jack, MP3 & Volume Control (PLMRMP3A) PREMIUM 4 CHANNEL AMPLIFIER: Engineered as a 4 Channel marine amplifier that allows high quality stereo reproduction from source. This will power up your speaker and universally compatible with a variety of head units like MP3 and smartphone. RCA STEREO INPUT: For an easier use of this hydra marine amplifier, it comes with premium RCA inputs. This also includes a 3.5mm-to-RCA adaptor so you can connect your device and a remote for volume control. SHORT PROTECTION: Has a built-in power protection circuitry and soft turn on/off. These are to protect the amp and your vehicle's electrical system from short circuit conditions. POWERFUL 400 WATT: This amplifier is powerful with its 400 WATT maximum power supply. Comes with adjustable input GAIN level controls of 2 to 4 Ohm speak. Its also waterproof