Q Power HD12 4HOLE Heavy Duty Quad 12 Sealed Subwoofer Enclosure Box. Qpower 12" 4 hole empty box 1" MDF. Please check the specific laws in the state for which you reside. Products must not be used or expired, in the same condition that you received them and with their original packaging. Products must be in the same condition that you received them with their original packaging and cannot be used or expired.