1/2″ Drive to 3/8″ Drive Impact Adaptor, 2-1/4″ Overall Length, Black Industrial Finish, Spring Plunger Socket Retention. Williams® USA # JHW4-2F • Specially heat treated for impact use to provide long life, safety, and durability • Spring plunger provides secure socket retention for safety and convenience • Suitable for use with pneumatic and electric impact wrenches • Made in the USA