Heko obi , is an informal, soft obi. The adult's heko obi is the size of a normal obi, about 20centimetres (7.9in) to 30centimetres (12in) wide and 300centimetres (9.8ft) to 400centimetres (13ft) long. Adult men wear the heko obi only at home, but young boys can wear it in public, for example at a summer festival with a yukata.