This is a cap that adjusts with a Velcro strap at the back. The inner circumference is approximately 56cm when adjusted to the smallest size. It has been used infrequently, so there is no yellowing and it is very clean. It has been home-cleaned, but there is a faint stain or dirt that couldn't be completely removed on the inside. It's not very noticeable, but please refrain from purchasing if you are concerned. #Tennis #Cap #Hat #Visor #Sun protection