The Apex Series PA454 Powersports amplifiers deliver efficient Class D power, from an ultra-compact chassis, designed to fit into tight spaces and withstand outdoor environments without missing a beat. Available with 4-channels of output power, the Apex Series PA454 includes selectable front/rear electronic crossover frequency adjustment for quick and easy installation. Plus, it has been engineered for harsh conditions, with power and performance to meet the needs of most audio systems.