Constructed of M-35 5% cobalt high speed steel for super abrasive resistance in tough metals. 135-degree split point reduces feed pressure for easier penetration without work hardening. Durable rubber-sided case for added impact resistance. Sliding latch design provides added security. Available with a variety of drill bit types and piece count configurations. Includes an Irwin Pro Set Case made of durable molded ABS resin, so it can hold up to anything the job site throws at it. Case includes a full-length metal hinge pin for maximum durability and long life, and bit identification is simple with easy-to-read size markings. Includes: (2) 1/16 In., 5/64 In., (2) 3/32 In., 7/64 In., (2) 1/8 In., 9/64 In., 5/32 In., 3/16 In., 7/32 In., 1/4 In., 5/16 In., and 3/8 In.