OOK Padded Professional Picture Hangers use one or two channels for the nails, depending on how much weight the picture hanger is to hold. The heavier Picture Hangers use two or more channels to distribute the weight on the hanger into two or more areas thus distributing pressure to the nails to further increase hanging security of heavier objects. The OOK needle pointed blue steel nails are re-usable and will not damage walls! The hook's center-of-gravity guides are hand welded and allow no play in the nails, so the nail glides straight into the wall at the perfect angle for a secure hold. The padded backing protects the walls surface. Hanger is ideal for plaster and drywall surfaces, no stud is required. Value Pack has hangers that holds from 5-100 lbs.