1. made of quality carbon steel 2. good heat treament 3. zinc plating 4. the breaking force is 3 times of WLL These hooks are purchased by the famous world class companies for many years.welcome to order. 1/4" Eye slip Hook, Grade 435/16" Eye slip Hook, Grade 433/8" Eye slip Hook, Grade 431/2" Eye slip Hook, Grade 43 high quality eye slip hook grade 43 (GR 43)