Oster Cryogen-X Pet Clipper Blade, 3F Oster Cryogen-X blades are made using a 12 step process that ensures superior Cutting quality Size-3F carbon-steel blade leaves hair a 1/2-inch in length Patented Cryogen-X process take the blade to -300 degree F for extra hardness Hand lapped for a smooth cut finish; Handcrafted in the USA Measures 1-6/7 by 3/4 by 2-1/7-inch; 1 year parts warranty