V-Belt | Sierra 18-15400 Sierra V-Belt V-Belt 40 inches effective length 29/64 inches top width High strength synthetic cords resist shockload failure Compression part is a special rubber compound that assures smooth and even transfer of load forces to the cords Rubber edges maintain smooth, positive, no-slip contact with pulley grooves for reliable energy transfer Clogs are molded to precise tolerances to improve flexibility and maintain cord support Replaces OMC 311606 Replaces Mercruiser 57-69143Q