H12 size is usually used to convert the fog lights (1999-2002 Jeep Laredo, Limited and 2006-2011 Cadillac DTS). It may fit the following sizes: 9040, 9045, 9055. H12 is available only for HID systems. Choose one of two available sets: 35W and 55W. 35W kit produces more light than your factory halogen bulbs and increases the vision significantly. A wide color range gives you more options to choose from. The most popular colors for the fog lights are 3000-6000K. Yellow lights (3000K) are suitable for bad climate because this color can cut through air moisture as compared to the white light. It is perfect for foggy, snowing and raining conditions.