[Portable Size]: Professional football chain clip is about 32.2 cm/ 12.7 inches, the length of the nylon marker strap is about 26.7 cm/ 10.5inches. It can be wrapped around the wrist or hung on the key chain for convenience. [Durable Material]: Football official chain clip is mainly made of nylon material, firm and sturdy, not easy to tear. The pattern on the surface is printed by thermal transfer process, which can be kept for a long time without fading. [How to use]: While using,slide the black plastic slider along the orange nylon strap to mark yardage from 0-50 in 5 yard increments and record the value. [Wide Application]: Yard officials football nylon marker is available for referees in youth games, high school, college and football league, also suitable for your daily training.