Sonic Tools 28-piece 3/8” set includes a 3/8” ratchet, 3/8” breaker bar, 4 extensions and even a universal joint. The kit includes shallow flank-drive sockets from 6mm to 22mm along with 3 spark-plug sockets thrown in (16mm, 18mm, and 21mm). Sonic ratchets and sockets are made from Chrome-Vanadium steel for durability and resistance to rust and corrosion.