This 16-piece insulated hex bit socket set (No. 25016-I) from Gray Tools includes seven SAE hex head sockets ranging from 1/8"-3/8" and seven metric hex head sockets from 4-10 mm, all of which feature dual-layer insulation in compliance with ASTM F1505 standards, providing user protection up to 1,000 volts in a variety of electrical applications. The set also includes an insulated 42-tooth round head ratchet and a 3-inch extension attachment. Each bit has its size clearly marked on the 5S dual-color foam organizer for easy identification. The sets are made in the U.S. and backed by a limited lifetime warranty.