Pack contains 6 sets (6x bellies 6x backs) of precision cut Crease fly blanks that I use in my own tying.  SMALL - 36mm long 32mm wide 2mm thick MEDIUM- 42mm long 36mm wide 2mm thick  Hard to put what hook model fits best as each size hook model different so much . Small I use the most in my own tying , and it's best suited to either the Ahrex SA220 #1/0 or the SL12 #4/0 big difference in sizes I know but the shank length are very similar. The Medium works well with either a Sl12 #6/0 or the Ahrex SA210 #3/0. *Pack contains the foam blanks only , the flies pictured is for display purposes only and is not for sale.