Self-adhesive for easy mounting, the 3-1/2 inch Anodized Aluminum Number 0 is constructed of aluminum for rust resistance and is great for labeling tool sheds, mailboxes and lockers. 3-1/2 inch size Number 0Anodized aluminum construction provides rust resistanceLabel tool sheds, mailboxes and lockersNon-reflective black number on a gold backgroundIt provides good visibilitySelf-adhesive for easy mounting