The Pyle Elite Series Amps provide waterproof power for all of your speaker needs. The marine grade waterproof construction and high-power efficiency ratings provide performance and reliability -- rain or shine! These multi-channel amplifiers are perfect for the back yard boat or even by the pool! Additional features include MOSFET power supplies built-in electronic circuitry protection heavy-duty aluminum heat sinks and more. Enjoy versatile waterproof performance and next level sound amplification with the Pyle Elite Series Amps. (Models: PLMRA200 PLMRA400 PLMRA420 PLMRA620 PLMRA820). DETAILSFeatures: 4-Channel Amp System Dual MOSFET Power Supply Marine Grade Construction Waterproof Marine Rating IP-01 Dual Adjustable Input GAIN Level Controls Dual High Level Speaker Input Connectors Dual RCA (L/R) Input Connector Jacks Gold-Plated Speaker Output Terminal Connectors Adjustable Input GAIN Level Control Anti-Thump Delay Circuitry Built-in Thermal Overload & Speaker Short Protection Heavy Duty Aluminum Alloy Heatsink Power ON LED Indicator Remote Turn ON/OFF Whats in the Box: 4-Ch. Marine Amplifier Audio Connection Cables Technical Specs: Output Power: 100 Watt x 4 MAX Amplifier Class: AB Fuse Type: 20A Input Gain Impedance Adjustment: 1 - 300mV Frequency Response: 15 - 30kHz +/-3dB Input Impedance: 10k Ohms (Low) 100 Ohm (High) Input Sensitivity: 250mV (Low) 2.5V (High) T.H.D.: