Filter Filters GMC Remove All Filters Price $100-$500 (205) $500 and above (20) Condition New (225) Brand Harmony Audio (225) Model Sierra (204) Envoy (9) Sonoma (9) Canyon (3) 01-06 GMC Sierra 1500 Crew Truck Harmony R104 Ported 10" Sub Box Enclosure $115.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony R104 Dual 10" Sub Box Enclosure $215.99 01-06 GMC Sierra 1500 Crew Truck Harmony F104 Ported 10" Sub Box Enclosure $134.99 2004-2012 GMC Canyon Crew Cab Truck Harmony F104 Dual 10" Sub Box Enclosure New $244.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony A122 Dual 12" Sub Box Enclosure $255.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony F104 Dual 10" Sub Box Enclosure $239.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony R124 Dual 12" Sub Box Enclosure $221.99 2001-2006 GMC Sierra HD Crew Truck Harmony A122 Dual 12" Rhino Coated Sub Box... $295.99 2001-2006 GMC Sierra HD Crew Truck Harmony R124 Dual 12" Rhino Coated Sub Box... $256.99 2002-2009 GMC Envoy SUV Harmony A122 Single 12" Custom Sub Box Enclosure New $145.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony F124 Dual 12" Sub Box Enclosure $264.99 1999-2006 GMC Sierra Ext Cab Truck Harmony R104 Single 10" Sub Box Enclosure $145.99 2007-2013 GMC Sierra Extended Cab Truck Harmony A122 Single 12 Sub Box Enclosure $160.99 2002-2009 GMC Envoy SUV Harmony R124 Single 12" Custom Sub Box Enclosure New $133.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony A102 Dual 10" Sub Box Enclosure $249.99 1999-2006 GMC Sierra Ext Cab Truck Harmony R124 Single 12" Sub Box Enclosure $140.99 1982-2004 GMC Sonoma Extended Cab Truck Harmony A122 Dual 12" Sub Box Enclosure $260.99 2001-2006 GMC Sierra HD Crew Truck Harmony R104 Dual 10" Sub Box Enclosure New $225.99 2002-2009 GMC Envoy SUV Harmony F124 Single 12" Custom Sub Box Enclosure New $159.99 88-98 GMC Sierra Ext Cab Truck Harmony F124 Dual 12" Rhino Sub Box & CXA800.1 $531.99 2001-2006 GMC Sierra HD Crew Truck Harmony R124 Dual 12" Sub Box Enclosure New $231.99 2001-2006 GMC Sierra HD Crew Truck Harmony F124 Dual 12" Rhino Coated Sub Box... $299.99 1999-2006 GMC Sierra Ext Cab Truck Harmony A122 Single 12" Sub Box Enclosure $150.99 1988-1998 GMC Sierra Ext Cab Truck Harmony R124 Single 12" Sub Box Enclosure $146.99 123456...10