Product Name: BMW F25 X3 Tail Lamp Replacement Circuit Board Module Set of 2 Brake Lamp Tail Light Genuine Compatible Compatibility: BMW F25 X3, Model Years 2011-2017 Compatible with all grades Useful when tail lamps don't light up. Since LED tail lamps are common, the possibility of bulb failure is low. If the lights don't turn on, a malfunction of the module circuit board is likely. Replacing only one side is also possible, but the lifespan of the parts is usually similar, so it is safer to replace both left and right sides at the same time.