ABS is defined as Acrylonitrile-Butadiene-Styrene which is blow molded plastic.
This is a specific type of plastic which is used in artificial nails for the actual tips. There are different options available, but some are designed to be more resistant to splits or cracks than others.
Daily Hair Tip
After you have removed hot rollers from you hair let the curls set for a minute. Use fingers or pick to carefully arrange curls so they don't droop.