1.Upstream location is between the catalytic converter and the engine.Downstream location is between the catalytic converter and the tailpipe 2. and long lifespan 3. It can improve the conversion rate of Oxygen in maximum extent 4. Perfect aftermarket replacement Placement of Vehicle:Front,Rear Manufacturer Part Number: 56028994AA, 56029049AA, 56041698AA, 56044627AA, 56044652AA Interchange Part Number: 23159, SG1849, 234-4587, 15510 Length:29inch(2pcs) and 22.4inch (2pcs) Compatible With: For 200 2010-2012 For 300 2005-2012 For 2007-2009 For 2004-2008 For 300M 2004 For 2004-2012 For PT Cruiser 2004-2010 For Sebring 2004-2010 For 2008-2012 For 2007-2012 For 2008-2012 For Charger 2007-2012 For Durango 2004-2012 For Magnum 2005-2008 For 2004-2006 For Neon 2004-2005 For 2004 For Grand Caravan 2004-2012 For Journey 2009-2012 For Nitro 2007-2011 For 2004-2010 For Viper 2004-2010 For 2005-2012 Ram 1500 For 2005-2012 Ram 2500 For 2005-2011 Ram 3500 For Compass 2008-2012 For Grand 2004-2012 For Liberty 2004-2012 For Patriot 2007-2012 For 2004-2012 For Commander 2006-2010 Material: Plastic+metal colour: black Package Contents: 4 x Oxygen Sensor Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.