Socket Set 21Pcs Gear Ratchet Combination SAE & Metric Features: • Fine tooth 5 ratchet handle • "Pass through" socket system eliminates the need for deep sockets • The GearRatchet" handle quickly converts to a conventional 1/4" or 3/8" ratchet for standard sockets by using the two included adapters Set Includes: • GearRatchet" handle • (7) SAE Vortex" sockets (3/8", 7/16", 1/2", 9/16", 5/8", 11/16" & 3/4") • (10) Metric Vortex" sockets (10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm & 19mm) • 1/4" Dr. GearRatchet" adapter • 3/8" Dr. GearRatchet" adapter • Vortex" Pass-Thru 3" extension (Designed to reach into deep recesses making deep sockets obsolete) • The Vortex" thin wall socket design has the same torque strength as an ordinary socket • Over all height is reduced by as much as 50%, width by 20% • The unique GearRatchet" drive configuration increases torque strength by as much as 40% and needs as little as 5 or arc • Chrome vanadium steel • Fully hardened