These check cords are constructed of the same multi-filament polypropylene roping used in all of Mendota’s products. These long lines are UV coated to protect against decay and fading, and are gentle on the hands. These trainers and super cords are the professional's choice for training to come on command and retrieving to hand. These check cords are made in St. Paul, MN USA Obedience 20: 3/8" x 20' - Black Trainer 30: 3/8" X 30' - Orange Trainer 50: 3/8" x 50' - Orange ProTrainer 30: 1/2" x 30' - Orange Super Cord 30: 7/16" x 30' - Hi-Viz Yellow Super Cord 50: 7/16" x 50' - Hi-Viz Yellow