Set of 4 Strong Multi Purpose Metal Wall Suspension Ceiling Hooks Hammock Swing Hook Can be used for suspension of all swings, hand rings etc. Suitable for indoor and outdoor use. Diameter: 3.5 inches (9 cm) Make sure the chosen screws/fittings are suitable for use in the wall/ceiling to which the curtain rod is to be mounted. Strong galvanized steel construction Suitable for indoor and outdoor use