●Uses: Extend sockets and reach narrow and deep places ●Drive: 1/2 inch (12.7 mm) ●Set Includes: 3.0 x 0.04 x 0.04 x 0.04 inches (75 x 1, 125 x 1, 200 x 1, 250 x ●Material: Chrome vanadium steel ●Extension bar set that can be used in narrow engines deep and narrow places in automotive and motorcycle maintenance