These are the same running pliers I use in my studio and they have given me years of quality service.
Running pliers derive their name from their unique curved jaw design which forces a score to "run" and break with incredible ease. Just position at the end of your score line and squeeze. The curved jaw exerts equal pressure on each side of the score so that your glass will break cleanly. Screw adjusts to any thickness of glass.
These "small" running pliers measure 6-1/2 inches long with 3/4" rubber coated tips. They are perfect for people with smaller hands. (The rubber tips are replaceable.)
Plastic dipped handles over metal. Great size and shape.