SK Hand Tools 4090 Fractional Socket SuperSet&ndash; 40-Piece 3/8-Inch Drive 6 Point Metric Accessories. High Visibility Impact Units SureGrip(R) Hex Design: SK impact sockets feature SureGrip hex design that drives the side of the hex, not the corner leading to increased strength. Power hand tools avoid rounding of rusted or damaged fasteners due to sharp cornered hex tool. Heavy Duty Socket Superset: metric ratchets are coated with a rust-preventative compound, which makes them exceptionally resistant to corrosive factors. Weather proof. Metal enclosures perform well even in harsh working environments SK 4090 Socket Assembly: 40 piece socket set. 3/8" Drive High Visibility Impact Sockets include 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm size options. 3/8" drive deep high visibility impact sockets are of 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm,15mm, 16mm, 17mm, 18mm, 19mm in size High Visibility Sockets: metric units are laser engraved every 120 degrees with extra-large markings for improved readability. Easy to recognize the measurements and types of these metric assortments Accessible Hand Tools: nose-down design of fractional utilities extends the taper as far as possible, for improved access over straight wall designs. Socket SuperSet includes standard and deep sockets in both fractional and metric sizes