PERFORMANCE METALLIC LACE: Sold as One Pair (Two Laces). Laces are flat and about 3/8 inch (9 mm) wide with hardened plastic tips. Multiple lengths available (pick your length). SPARK by Derby Laces create a natural friction when tightened to help them stay tied, tight, and where you want them. SUITABLE FOR: Children and Adults. Regular Shoes, Skates, Boots, Hockey and Roller Derby. HARDENED PLASTIC TIPS: SPARK by Derby Laces feature a hardened plastic tip that is extremely durable. DURABLE FIBERS: SPARK by Derby Laces are braided laces made out of metallic coated durable fibers. They have a unique texture that allows them to tighten and loosen easily.