Actually they are the serpentine belts used on modern cars.
They work fine on the flat pulleys. I've been running them for years on my cars. Plus if you ever break down they are available at most auto parts stores.
Frank ---
Where Are You From? Hookstown, Pennsylvania
Do You own a car built by Durant? 17 Durant & Star cars & a Durant Dort buggy (one horse power)
Napa Serpentine Belts are the best. They won't keep stretching. Just a word of caution. Don't over-tighten them. Could cause the fan bearing to run hot. Fritz
Where Are You From? Cleveland, ohio area
Do You own a car built by Durant? 1928 Durant M-2 sedan