There are three different roof hooks that we carry. Each one has some benefits, and some drawbacks. All three are made of steel.
The basic is made by Werner Ladder, it is the 15-1 Steel Folding Roof Hook and is permanently installed on a ladder. The Werner 15-1 is spring loaded and pivots at 90 degrees, if you have a dedicated ladder to use this product might be great for you. But, it has points that tend to bite into the shingles, which often times is not desirable.
The second product is made by Tranzporter Roof Zone. It is made in China and is Zinc-plated. The Roof Zone 65005 is designed to attach to a ladder, but the manufacturer suggests that two are used.
The third and best product is made by Acro Roofing Products. Manufactured in the USA, Wisconsin to be specific, this product is the best choice. The Acro 11082 is designed to attach to a ladder and only one is needed.