This Snap-on Tools USA socket set includes a 4-piece set of 1/4″ and 3/8″ and 1/2 drive adaptors and swivel socket. The sockets are made with a black oxide surface finish and are compatible with both specialty and standard drive types. The set is ideal for automotive applications and is manufactured in the United States. The set includes sockets, adapter, and universal/swivel tools, making it a versatile addition to any toolbox. The size of the sockets is 3/8in. And they are designed with a system of measurement that includes specialty, SAE, and metric measurements.