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 Perfect 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.