Features 1. The socket adapter is made of heavy-duty chrome-vanadium steel, which is durable and has a long service life. 2. The surface of each adapter is galvanized and blackened to ensure corrosion resistance. 3. The main body of the adapter is designed with a spring loaded ball stop and a small hole to keep your outlet quiet and safe. 4. There are four different sizes of socket adapters that can be used for different sockets. 5. Common size combinations increase the area and capabilities of many outlet groups. Description: This is a 4 pieces of socket adapter and reducer set. Heavy duty chrome vanadium steel construction is designed for use with drivers and wrenches. A black oxide finish makes each piece anti-corrosion and very durable. Spring-loaded ball detent keeps your sockets still and secure.   Features: 1. The socket adapter is made of heavy-duty chrome-vanadium steel, which is durable and has a long service life. 2. The surface of each adapter is galvanized and blackened to ensure corrosion resistance. 3. The main body of the adapter is designed with a spring loaded ball stop and a small hole to keep your outlet quiet and safe. 4. There are four different sizes of socket adapters that can be used for different sockets. 5. Common size combinations increase the area and capabilities of many outlet groups.   Specifications: Material: chrome vanadium steel Surface finishing: electroplating, blackening Quantity: 4pcs Color: silver, black ( Optional ) Weight: Approx. 133g Size: 1/2"(square hole)--3/8"(square head) 3/8"(square hole)--1/4"(square head) 3/8"(square hole)--1/2"(square head) 1/4"(square hole)--3/8"(square head)   Package Includes: 4 x Socket Reducers Package List