In the construction industry, the ratio of fatal accidents caused by a fall remains higher than any other industry at 60%. Although a fall prevention rope is a must, accidental falls constantly occur at the time of replacing a hook when moving at high places. The structure of this hook is designed to be replaced easily, and has realized the idea of having a wider opening without making the whole assembly bigger. The detachment prevention lever which imitates a finger serves to provide slip prevention and increases stability when grasping it. These design ideas made it possible to widen the opening by 116% compared to other conventional products in the market. Using this design for a forged aluminum hook made the hook lighter by 68% compared to conventional ones. The excellence of the material is underlined by a mat black coating, which makes this product beautiful.