High-quality iron material: The roof rack is made of iron, stable and painted with gray paint, durable, no rust, corrosion-resistant, wear-resistant, not easy to be damaged over time Heavy Duty Roof Hook: Designed with a strong heavy duty hook for safety, the maximum load is 300kg, please make sure the beam is the right size and supported before installation TWO INSTALLATION WAYS: Our brackets are pre-drilled for easy installation. You will receive 2 concrete anchors for concrete decks and 2 hex screws for wood decks with 2 washers for installation in minutes. UNIVERSAL USE: Best use as a ceiling hook for hammock chairs, hammocks, porch swings, rocking chairs, punching bags, yoga towels, sling trainers, awnings, hanging seats, or for hanging any other heavy objects from overhead supports. Optimum dimensions: Roof hook diameter: 120mm, Concrete anchor length: 90mm, Hex screw length: 85mm. Includes a ceiling hook, 2 screws for concrete applications, 2 screws with 2 washers for wood applications.