Includes hex keys in sizes: .050', 1/16', 5/64', 3/32', 7/64', 1/8', 9/64', 5/32', 3/16', 7/32', 1/4', 5/16', and 3/8'. Keys are made of 8650 chrome nickel alloy steel for maximum performance. Keys come in compact plastic holder that firmly retains the keys in size marked holes. Slide blister packaging is reusable for storage on pegboard by user.