The Mayhew Tools 9-Piece Triple Square Socket Bit Set includes 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, and 18mm. Socket bits can be used with the appropriate ratchet, T-handle, or socket spinner handle. Bits made from S2 tool steel with proprietary heat treat for superior strength and durability. Precision tip profile manufactured for positive and precise fastener engagement. Sockets made from alloy steel with proprietary heat treat for long life and lasting performance. Fully polished, chrome plated sockets for superior corrosion resistance. Design of socket and bit assembly allows for easy replacement of broken or worn bit. Tip sized appropriately to 1/4-Inch, 3/8-Inch, and 1/2-Inch square drives for maximum torque and minimum damage to tips or fasteners. Bits and sockets made to exacting specifications. Includes color coded storage rail.