Forget the tedious job of trimming scraps of sheepskin and stuffing all that thru a rectal sized orifice on the bottom of your buck rolls. These foam inserts offer a quick solution and very consistent feel from one pair to the next. One size only- 36D which makes an average medium sized pair of buck rolls. Also you may wish to buy the pattern pack (120317-A)and DVD (#122918) that goes along with the inserts.