Reliable Material:Roof Ladder hooks Made of heavy-duty Rectangular Steel Tube with water and rust-proof finish, ladder roof hook has 500 pounds bearing capacity, moreover the universal wheel makes it easier to slip the stair onto the roof, saving labor and time.Ladder stabilizer Fits to most little giant ladder and other. Unique Design:(Patented) 1. The ladder roof hook design four mounting holes you can select the appropriate mounting holes ,according to the ladders with different spacing steps, in order to achieve the desired effect, Attaches to any style extension ladder. 2. Rubber Grip T-Bar for Damage Prevention Compatible with round or D rung styles,Two hooks must be used per ladder.