Delivery includes groove nails. The colored hooks are hot-dip galvanized and powder-coated. They should be installed centrally on the rafters. A minimum of two hooks is required for the first ladder, and at least one hook for each additional ladder. In accordance with the Construction Products Regulation (BauPVO) 305/2011 (EU) and DIN EN 517, safety roof hooks must be installed on roofs with a slope of 22.5° to 75°. They should be distributed on the roof surface as follows: The upper row should be less than 1.0 m below the ridge; intermediate rows should be spaced less than 5.0 m apart from the row above; the lower row should be less than 1.5 m above the eaves, measured along the roof slope. The horizontal distance between safety hooks in a row must not exceed 2.0 m. To be used at eave heights over 3.0 m.