Dayco 15225 V Belt Replac Top Cog V-Belt The Dayco Top Cog V-Belt delivers more flexibility, and increases airflow around the belt, so it runs cooler and lasts longer than most competitive belts. Three plies of neoprene impregnated fabric resist heat, oil, and grease, and a specially formulated treatment of the polyester cord provides the strength, stability, and reliability that are required of a "national brand" v-belt.