Rubber core, polypropylene jacket. Plastic injection hooks. Includes 2-Piece of 9 mm x 18 in (Orange Cord), 2-Piece of 9 mm x 24 in (Orange Cord), 2-Piece of 9 mm x 32 in (Orange Cord), 2-Piece of 8 mm x 40 in stretch cord w/adjustable hook, 4-Piece of 4 mm x 12 in heavy-duty toggle cord, 4-Piece of 7 mm x 30 in adjustable elastic cord (Orange Cord) and 8-Piece of 4 mm x 10 in mini stretch cord.