The PD525S is a high power low frequency loudspeaker comprised of two 380 mm (15 in) Dual Coil - Dual Gap Differential Drive®, VGC low frequency drivers in a front-loaded, vented configuration. The trapezoidal cabinet is fitted with M10 threaded suspension points. Ideal for direct exposure or extreme environments, such as tropical or beach, or in areas with salt air, extreme high humidity or rapid changes in temperature.