Each set comes with a 8.5″ x 12″ cutting mat and an Excel Blades K1 Aluminum Knife, and 5 pack of #11 replacement blades. Includes (1) K1 Knife, (5) #11 Blade, (1) Cutting Mat. The K1 handle holds the following blades only: # 5 / 6 / 10 / 11 / 21 / 12 / 13 / 16 / 17 / 17A .