Powerpack - High Output Dual 12" RAD Fan/Alum Shroud Kit w/ PWM Controller Get complete control of your engine temperature! Derale Performance has combined their high-performing shrouded Powerpacks with the ultimate fan controller. Using high output electric fans incorporated into an engineered shroud, this Powerpack can conquer even the most difficult cooling conditions. This unit features an aluminum shroud measuring 28 1/4" wide by 17" top to bottom and is only 4" in overall depth to offer an adjustable yet precision fit. The natural, non-finished aluminum shroud gives the user the freedom to polish, anodize, paint, or simply leave it raw to create a truly custom look for an affordable price. The dual 12" high output electric fans are some of the most proven and reliable fans in our line-up and are specifically designed to thrive on thick, tight fin radiator cores. Offering a total of 4000 CFM, this dual electric fan assembly generates the most real-world airflow in the smallest package on the market. Now add the PWM Fan Controller with built-in soft start technology. The controller utilizes Pulse Width Modulation to constantly adjust electric fan speeds from 0-100%, maintaining the optimal engine operating temperature. No more reacting to the engine temps, you can control it! This allows electric fans to operate at the percentage needed, instead of 100% all the time, therefore increasing component life and eliminating amperage spikes. Powerpack - High Output Dual 12" RAD Fan/Alum Shroud Kit w/ PWM Controller