Our 100% advanced para-aramid fiber boot laces have a number of advantages that make them perform and last in the most unforgiving environments. They are, quite simply, the strongest, most durable shoe/boot laces in the world! Ironlace Unbreakable Round Bootlaces are lab-tested and guaranteed for life. They are proven to be 10x stronger than steel, 20x longer-lasting than Kevlar laces, and feature a higher strength-to-weight ratio than carbon fiber. Our laces have an amazing 1500-pound breaking strength/pair and a ⅛ inch (3.2mm) diameter that will fit any boot and never break when pulled tight. These shoelaces have been field-tested in the most abusive environments and are proven to be damage, cut, abrasion, wear, chemical, UV, and corrosion resistant.These versatile, indestructible boot laces are equipped for almost any application. They are non-magnetic and will not set off metal detectors, freeze, or burn in extreme temperatures. Ironlace shoelaces are waterproof, heat-resistant, and fire resistant up to 630 degrees Fahrenheit/332 Celsius. These are the ideal laces for firefighting, welding or any worker that puts their boots to the test day in and day out.Our stretch-free, non-slip laces stay comfortable and secure in even the harshest indoor and outdoor environments. They are long-lasting, and colored to match up to 99% of common black, beige, grey, tan, and brown boots. When you spend weeks and months on the road or at the job site, having a broken lace is disruptive at best. Save yourself money, time, and frustration by opting for the world’s most reliable laces.