There are many compounds to choose from. You can download our PDF compound guide to better assist your decision. The letter in the center of Hawk's part number designates their compound material. Depending on the brand of caliper that you're using, you might have to drill the center mounting hole of these pads.

The HB104 shape is only available in 0.485" thickness

Also if you have aftermarket calipers and you're not certain which pad they use you can download Hawk's Specialty Caliper Guide. Depending on the brand of caliper that you're using, you might have to drill the center mounting hole of these pads.