Their premier multifilament string, Babolat Xcel 17 Blue is designed to offer players an ultra comfortable feel with added durability. Utilizing highly elastic polyamide fibers, this string offers greater elasticity and tension maintenance. Xcel features a polyurethane resin that increases comfort as well as durability by ensuring adhesion between individual fibers. The dual coating of polyurethane followed by polyamide provides a friction barrier, resisting string burning and notching to extend the life of the string. This string is highly recommended for players seeking ultimate comfort with additional durability.