My Mercedes E350 4Matic (W211) didn't have all tire pressure sensors when I bought it used. So in my head I was always wondering if the tire pressure was low because the indicator light was always on. With the purchase of this Android tire pressure monitoring system, it didn't take long to install and it also works very accurately. The seller was great, very fast delivery and also emailed to see how everything went after I received the item. I don't often give reviews unless they're usually negative, but I'm willing to give credit where it's due and this product deserves it.