Lace STRONGER THAN STEEL: Our durable, 100% advanced para-aramid fiber replacement lace is 10x stronger than steel; Amazing 1500-pound breaking strength/pair and an inch (3.2mm) diameter means they will fit any boot and will never break when pulled tight. A PERFECT MATCH: Use with almost any brand and style of shoes or boots; Our tough, unbreakable laces are colored to match up to 99% of the most common black and brown boots on the market and trusted by hundreds of thousands of loyal customers. Measure old laces to determine size needed for new laces. STAY PUT & STAY COMFORTABLE: Stretch-free, non-slip shoelaces lace up tight for a strong fit that stays tied; Once you put them on, stays put and stays comfortable whether you're on the job site, trekking through snow, or hiking a mountain. GUARANTEED FOR LIFE: Long-lasting, durable laces field-tested in the most abusive environments; They are 20x longer-lasting than Kevlar laces, and proven to be damage, cut, abrasion, wear, chemical, UV, and corrosion resistant. WATER, HEAT & FIRE RESISTANT: Shoelaces are waterproof, fire resistant, and heat-resistant up to 630 degrees Fahrenheit/332 Celsius; The ideal laces for firefighting, welding, or anyone who works or plays hard and expects their equipment to last.