The Boa® Lacing System provides custom-comfort with smooth, even closure and no pressure points. Easy, one-handed adjustment with a secure hold that is built to last. Featuring a wire lace made of 49 strands of aircraft-grade stainless wire cable and bombproof nylon reel guides that are designed to take all of the abuse that you can throw at them. The system is designed to be easily user-repairable and replaceable. Request free replacement parts online via the Boa® Dialed In for Life™ Guarantee.