4 CHANNEL BRIDGEABLE AMPLIFIER: Pyle’s PLMRA420 is engineered as a 4 Channel bridgeable marine amplifier that powers up your speaker and is universally compatible. It also has high and low electronic crossover network or pass filters PREMIUM RCA INPUT: For an easier use of this hydra marine amplifier, it comes with premium RCA inputs. If your marine receiver lacks RCA output jacks, you can connect speaker output leads to the high level inputs SHORT PROTECTION: Built with a heavy duty Aluminum Alloy heatsink, thermal overload speaker short protection and LED light indicator. These are to protect the amp and your vehicle's electrical system from short circuit conditions POWERFUL 1000 WATT: This amplifier is powerful with its 1000 WATT maximum and dual MOFSET power supply. Comes with dual adjustable input GAIN level controls of 10k Ohm (Low) and 100 Ohm (High) speaker impedance MARINE GRADE: With its Marine rating of IP-01, it is waterproof ready. It’s constructed with gold plated speaker output terminal connectors as well to combat corrosion with long term use Waterproof four-channel, bridgeable MOSFET power amplifier with 4 x 250 Watts maximum output Variable high- and low-pass filters with crossover mode selector High-level MOLEX and gold-plated low-level RCA inputs with adjustable input level Overload, Short Circuit, and Thermal protection with LED indicator Variable bass boost of up to 18dB at 60Hz This Pyle Hydra amp will power your speakers on the dock, in your boat, or by the pool--it's completely waterproof. This four- channel, 1000-watt bridgeable marine amp takes both high- and low-level inputs, so it's compatible with a variety of head units and sources. Use in stereo, or double the power by bridging inputs. Comes with variable electronic crossover network, variable bass boost, and variable gain control for total control over your sound. A blue LED level display lets you keep an eye on your signal, and for protection, you can count on the thermal, overload, and short circuit protection. Runs on 12 volts DC. Power your speakers on the dock, in your boat, or by the pool. Click here for a larger image View a feature diagram. Click here for a larger imageInput OptionsThe PLMRA420 features gold- plated low-level RCA inputs for sources that use RCA-type connectors. If your marine receiver lacks RCA output jacks, you can connect speaker output leads to the high-level MOLEX inputs.Input Level ControlAdjust the line level input for the least amount of distortion to match your source unit.Bass BoostAdd a little low-end boost with selectable bass boost of up to approximately 18dB at 60Hz.High- and Low-Pass FiltersOptimize the output to match your speakers exactly, using the variable high-pass and low-pass frequency controls.Crossover Mode SelectorRoute the output of the low-pass or high-pass filters or the full signal to the internal power amplifier, or the full range if preferred.ProtectionProtect the amp and your vehicle's electrical system from short circuit conditions with built-in fuse protection, along with overload, thermal and short circuit protection. LED lights indicate if the amp has gone into a protection mode. Finally, an anti-thump turn-on feature protects your speakers during power-up.Pyle PLMRA420 Select Specifications Power Rating: 250 Watts x 4 Maximum Output at 4 ohms 35 Watts x 4 RMS at 4 ohms 50 Watts x 4 RMS at 2 ohms T.H.D: <0.04% S/N Ratio: > 95dB Power Supply Voltage: 14.4V DC Neg. Ground (10.5-16V) Frequency Response: 15 Hz-30 KHz Input Impedance: Low Level: 10K Ohms High Level: 100 Ohms Input Sensitivity: Low Level: 250mV High Level: 2.5V Dimensions: 10.9 x 2.7 x 12 Inches (L x W x H) What's in the BoxPyle PLMRA420 Amplifier, Mounting Hardware, User's Manual