LOCK LACES are 48" in length and can stretch up to 72". The laces are a one size fits all for both children and adults. It is recommend that the user's foot is inserted in the shoe during the installation process prior to trimming the excess lace 2-3 inches from the Lock device then attaching your Cord Clip end piece. Each package of LOCK LACES contains 2 laces, 2 Lock devices and 2 Cord Clip end pieces suitable for lacing up 1 pair of shoes. Who can wear LOCK LACES? LOCK LACES are ideal for everyone, from runners and triathletes, to kids, senior citizens and individuals with special needs. LOCK LACES also give some users the independence and confidence to slip on and off their shoes without having to depend on others for assistance. LOCK LACES are also fashionable with their catchy colors which match most shoe brands and models (who wants to wear Velco)! What separates LOCK LACES from their competitors and other products is the overall quality of the lacing system which includes being water resistant, durability, ease of use and simple installation. The laces are elastic which give the user an extra stretch-fit comfort and support by conforming to the users foot which reduces heel slippage and pressure points along with increasing blood flow throughout the foot.