Purpose-built for the marine environment . the Signature Series marine amplifiers feature some of the most impressive protection from the environment available ?? delivering a Signature performance out on the water. Built on the True-Marine design philosophy from Fusion . the Signature Series amplifiers have been tested to a high level of protection against salt fog . temperature . vibration and UV. The highly efficient Class-D design provides lower battery drain with a higher output than Class-AB amplifiers. This delivers increased power to the connected speakers/subwoofers for a whole new level of audio performance. The Signature Series amplifiers feature built-in variable bass boost . a subsonic filter and variable low/high pass crossover filters for superior performance and enhanced system protection.