SPX-17PRO - Alpine 6.75" Type-X Pro Series Component Speaker System Component speaker system includes 2 woofers, 2 tweeters, and 2 crossovers 6-3/4" hybrid glass fiber woofer with Natural Butyl Rubber Multi-Roll surround 1-1/4" ring-radiator tweeter 2-way external crossover network with 4-level tweeter control and 6 phase link modules Top-mount depth: 2-9/16"