The 2015 Jeep Grand Cherokee Altitude uses an H11 bulb for the low beams. This means that you will need to get an H11 Hid kit
to upgrade the low beams on the vehicle.
When upgrading the low-beams on the vehicle to HID, you will need account for the vehicle's canBUS system -- which will make your new lights flicker if you don't. You will need to use coupon code "MOPARHID" at checkout to ensure you get the proper harness for this upgrade, which will eliminate you having any flicker issues.