This Package Includes the Following Items:
1 x Custom Chevy Silverado 07-13 Subwoofer Box Extended Cab Dual 12"
2 x Harmony Audio HA-R124 Car Stereo Rhythm Series 600 Watt Single 4 Ohm 12" Sub

Custom Chevy Silverado 07-13 Subwoofer Box Extended Cab Dual 12":
Features:Dual 12" 2007-2013 Chevy Extended Cab Sub Box
Mounting Depth: 6"
Air Space: 0.60 Cubic Feet Per Sub
Sealed Enclosure
Dimensions: Width 55-3/4" x Front Height 8-3/4" x Rear Height 5" x Depth 14-3/4"

Constructed with High Quality MDF
(2) High Quality Binding Terminal Cups (Accepts Banana Terminal Plugs OR Bare Wire 'up to 10GA')
High Quality Black Carpet
Enclosure installs under rear seat down firing
This box fits: 2007-2013 Chevy Silverado Extended Cab
2007-2013 GMC Sierra Extended Cab

Harmony Audio HA-R124 Car Stereo Rhythm Series 600 Watt Single 4 Ohm 12" Sub:
Specifications: 12" Rhythm Series Car Subwoofer
Power Handling: Peak: 600 watts
RMS: 300 watts

Sensitivity: 88.2dB
Frequency Response: 27Hz-1.8kHz
Mounting Depth: 5 11/16"
Mounting Cutout Diameter: 11 1/8"
Min Sealed Box Volume (Cubic Feet): 1.25
Max Sealed Box Volume (Cubic Feet): 3.52
Min Vented Box Volume (Cubic Feet): 1.65
Max Vented Box Volume (Cubic Feet): 2.3
Single 4 Ohm