4L section V-belts are light duty belts for fractional horsepower (FHP) applications. They have a nominal top width of 1/2" and a nominal thickness of 5/16" (actual dimensions may vary slightly). FHP V-belts, identified with an "L," are single belts used on drive systems that are typically operating at 3 HP or less. These V-belts are often used in HVAC equipment and appliances.