OBCON Single 10-Inch Ford F150 04-11 Super Crew Cab Speaker Box -Driver side With Labyrinth Power Port
High Output with Labyrinth Slot Vent Ported Design  10" Single Subwoofer Box   Designed for:     Ford F-150 Super Crew '04-Current     Holds 1ea 10" Sub Woofer (Up Fire) Speaker Mounting depth 5 1/4" Tri-Lock Joint Construction What is Labyrinth Slot Vent Porting?  Look Here!