Dark Gray U-Lace Kiddos No-Tie Laces. Modular laces that are uniquely true-woven for an authentic look and feel. Usage: U-Lace Kiddos was designed specifically for Children ages 4 to 13 years old and for use on classic-style sneakers. As seen on Shark Tank. 2015 Winner - Parent Tested, parent Approved Award. 60% Polyester, 40% Lycra. Do Not Wash. OSFM (Child Ages 4-13).