ZENclosures 2011 - 2014 Kia Optima Subwoofer Box FEATURES: Warranty - 1 year Mounting depth - 9.00" Mounting hole size - 9 1/8" for 10" subs & 11 1/8" for 12" subs (Adjustable by request) Volume of airspace - 2x chambers with 0.89ft^3 airspace per chamber/subwoofer Adjustable by request (we can only reduce the airspace) Chambers - 2 for two subs, 1 for one sub Style - Sealed Construction - Premium MDF MDF thickness -0.75" Finish - Carpet Terminals - 2 Subs & Amps not included. This is a one piece box..... NO ASSEMBLY REQUIRED. The box is installed directly through the trunk opening and slides into place directly below the rear dash. NOTES: WILL NOT FIT HYBRID MODEL If you have a subwoofer that requires less airspace please let us know in the message area during check out. We do not charge extra for adjusting the airspace to your subwoofers needs.