Crescent Metric Deep Impact Socket *Socket Size: 21 mm *Drive Size: 1/2 in. drive *Metric or SAE: Metric *Number of Points: 6 Point *Style: Deep *Product Type: Impact Socket *Number in Package: 1 pc. *Impact Rated: Yes *Length: 21 in. *Packaging Type: Carded *Material: Chrome Vanadium Alloy Steel *Specially formulated and heat-treated for high strength and superior resistance to abrasion and corrosion