Filter Filters GMC Remove All Filters Price Under $50 (69) $50-$100 (44) $100-$500 (223) $500 and above (20) Condition New (356) Brand Harmony Audio (346) Kicker (10) Model Sierra (210) Sonoma (15) S-15 Jimmy (13) Sierra Classic (11) Safari Mini Van (10) Envoy (10) Suburban (10) S-15 Envoy (7) Savana Full Size Van (7) Show More S-15 C/K Pickup (6) Sierra HD (6) Acadia (5) S-15 Sonoma (5) Sierra 3500 (5) Sierra 2500 (5) S-15 Canyon (4) Canyon (4) Sierra 1500 (3) Sierra 2500HD (2) Sierra 3500HD (2) Sierra Chassis Cab (2) Acadia Limited (2) Savana (2) Safari (2) Van (2) Yukon (2) Jimmy (1) Yukon / Denali (1) Yukon Denali (1) Yukon XL (1) 2007-2013 GMC Sierra Ext Cab Truck Harmony R124 Dual 12" Sub Box & CXA400.1 Amp $362.99 88-98 GMC Sierra Ext Cab Truck Harmony F124 Dual 12" Rhino Sub Box & CXA800.1 $531.99 01-06 GMC Sierra 1500 Crew Truck Harmony R104 Ported 10" Sub Box Enclosure $115.99 Compatible with 2007-2013 GMC Sierra Crew Cab Truck Harmony F124 Dual 12" Sub... $534.99 Compatible with 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony F124 Dual 12"... $519.99 2001-2006 GMC Sierra HD Crew Truck Harmony A102 Dual 10" Sub Box & CXA800.1 Amp $479.99 Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony R124 Dual 12"... $357.99 Compatible with 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony A122 Dual 12"... $405.99 Compatible with 1999-2006 GMC Sierra Extended Cab Truck Harmony A122 Single... $310.99 2007-2013 GMC Sierra Extended Cab Truck Harmony F124 Single 12 Sub Box &... $309.99 Compatible with 2001-2006 GMC Sierra HD Crew Truck Harmony R104 Dual 10" Sub... $310.99 Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony A102 Dual 10"... $390.99 Compatible with 2007-2013 GMC Sierra Crew Cab Truck Harmony F124 Dual 12" Sub... $450.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony F124 Dual 12" Sub Box Enclosure $264.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony R104 Dual 10" Sub Box & CXA400.1 $356.99 01-06 GMC Sierra 1500 Crew Truck Harmony F104 Ported 10" Sub Box & CXA400.1 Amp $274.99 99-06 GMC Sierra Ext Cab Truck Harmony F124 Dual 12" Rhino Sub Box & CXA800.1 $551.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony R124 Dual 12" Sub Box Enclosure $221.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony R124 Dual 12" Sub Box & CXA400.1 $371.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony A122 Dual 12" Sub Box Enclosure $255.99 Compatible with 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony R104 Dual 10"... $310.99 Compatible with 2007-2013 GMC Sierra Ext Cab Truck Harmony F124 Dual 12"... $545.99 Compatible with 2007-2013 GMC Sierra Extended Cab Truck Harmony A122 Dual 12"... $430.99 01-06 GMC Sierra Non-HD Crew Cab Truck Harmony F104 Dual 10" Sub Box Enclosure $239.99 123456...15