Hat stretcher has Two Size: Small Size Available From 6 11/16 to 8 7/8 ;Large Size Available From 7 1/4 to 9 7/8；Small Size choose 6 1/2,Large Size choose 7 1/4 Three Colors of Thread Rod Available:Black, Red, Blue Stretch Hats Back To Their Original Size There is no splintery edge on any side which may hurt you or your hat Works on any hat which has soft material