Make an impact. Hilti's SI-S line of Long pact sockets offer long-lasting durability under the most stressful applications. Used for fastening lag bolts, steel bolts, high strength steel bolts and concrete screw anchors, S-NSD impact sockets feature a 1/2 in. square drive anvil and are constructed of CrMo alloy steel for added strength, wear resistance and reliability. 3 in. long version provides extra length for fastening in hard to reach areas. Perfect partner for use on corded or cordless impact drivers. Great for tightening nuts and bolts and driving and removing screws.