Professional Products Power Force harmonic dampers are not only affordable, but they are also extremely durable. These dampers feature a bonding process which adheres the elastomer to the inner diameter of the inertia ring and the outer diameter of the hub, utilizing a strong adhesive along with an improved elastomer to create a much stronger bond. These high-quality Power Force dampers also feature clear, white, easy-to-read timing marks against a painted black background. In addition, Professional Products engraves a mark every 90 degrees, which is also painted white (90 degrees marks are not on small block Ford dampers). These dampers are accurately balanced and closely machined for the correct fit.