Rockville RQ12TB Single 12" Triangle Ported Subwoofer Sub Box BedLined Enclosure Rockville RQ12TB Single 12" Triangle Ported Subwoofer BedLined Enclosure. Finished with Durable Bed Liner. 3/4" MDF. High Quality Spring Loaded Terminals. Air Space: 2.2 Cubic Feet. Tuning Frequency: 54 HZ. Product Dimensions (H x W x D): 16" x 22.75" x 14" inches. Rockville RQ12TB Single 12&#034; Triangle Ported Subwoofer BedLined Enclosure Finished with Durable Bed Liner 3/4&#034; MDF High Quality Spring Loaded Terminals Air Space: 2.2 Cubic Feet Tuning Frequency: 54 HZ Product Dimensions (H x W x D): 16&#034; x 22.75&#034; x 14&#034; inches