Very shallow mounting depth (4.62 in / 117 mm). No pole vent: permits mounting close to rear wall of enclosure. Extremely small sealed enclosure volume requirements. Long linear excursion capability (0.40 in / 10 mm, one-way). Patented “concentric tube” architecture. Patented “floating cone attach method” technology. Cast alloy frame with flat edges for tight driver grouping. Injection molded, mica-filled polypropylene cone. Steel mesh grille included with each driver.