THE POWERSTROKE PRO CLEAR FEATURES ENHANCED MIDRANGE AND LOW FREQUENCY TONES WITH ADDED ATTACK AND PROJECTION. CONSTRUCTED WITH 1-PLY OF 10-MIL CLEAR FILM WITH OUR PRESSURE DAMPENING PROFILE AND PERMANENTLY MOUNTED ACOUSTIC FOAM. THIS PROVIDES MAXIMUM VOLUME AND PROJECTION, WHILE PRODUCING CONTROLLED HIGHS, ENHANCED MIDRANGE AND LOW FREQUENCY TONES. AVAILABLE IN SIZES 18 - 24.