Marine certified: YES - Longer life against harsh conditions. Protected against sun fade with UVA paint coating. Conformal coated crossover components protect against fresh and salt water spray as well as dust and sand. IPX67: YES - Tested to the highest Marine and Motorsports standards for resisting the elements. Tweeter materiaL: Titanium Dome Tweeter - Very smooth musical response, high output with minimal required amplifier power. Marine certified crossover: Marine Certified Crossover - Conformal Coated, Butterworth 12dB per octave crossover with PTC (Positive Thermal Coefficient) tweeter protection. Dimensions: 22.6 x 13.5 x 16.75 in. Features of NA2-400.2: MB QUART NA2 400.2 400w 2-Channel Amplifier Amp For Polaris/ATV/UTV/RZR/CART. Marine Grade Protection: Yes - Amplifiers are ABYC & ASTM certified which defines that marine amplifiers must use conformal coated PC boards to resist corrosion from salt spray & moisture. Pre-Amp Circuitry: Q-Stasis Pre Amplifier Stage - The highly engineered Q-Stasis pre-amplifier stage reduces incoming noise from source units dramatically improving sound quality. Inputs: 1 Pair, RCA Nickel-Plated - High temperature impact resistant with hex screw terminals that allow for secure connections and is erosion resistant. Operation Mode: Two channel operation - Flexible installation allows this amplifier to run in two channel or bridged mono mode. Crossover / Signal Shaping: Switched FULL / LPF / HPF - Complete control of amplifier signal, essential when using two or more amplifiers. Class / Topology: Full Range Class D - Highly efficient circuit topology which helps the amplifer develop a lot of power in a very small heatsink. Output Devices Technology: PWM MOSFET Power Supply - Stable power through the PC board with minimal heat generation. Heat Sink: Aluminum - Quickly dissapates heat to allow the amplifer to run lower impedance for longer duration. Power Supply: Simpatico Coil Design - The dual coil Pulse Width Modulated power