A child harness (alternative: child tether, walking harness, British English: walking reins) is a safety device sometimes worn by children when walking with a parent or carer. Child harnesses are most commonly used with toddlers and children of preschool age, though they may also be used with older children, especially if they have special supervisory needs such as ADHD or autism. Various types exist, though all are worn by the child and have a lead (tether) or rein which is held by a parent or caregiver. As child harness designs and purposes have evolved with cultural norms and parenting techniques, they have become subject to common debate.