Self-closing hooks are getting more and more popular with our customers. While they are not new by any means, they are becoming more prevalent with more manufacturers. This has helped to create competition and push the price down on some brands, such as this one. These Cartec hooks are made from Grade 100 alloy steel. They are heat-treated and proof-tested with full product traceability. Many consider them safer to use than traditional sling hooks because their latch is made from alloy steel, is very durable, and it engages as soon as a load is applied.