Safety sign, danger confined space do not enter, aluminum, 7 x 10 features: signs identify and indicate potential, type, and degree of hazards that may lead to accidental injury or property damage. comply in accordance with osha 29 cfr 1910.145 and ansi z535 requirements thick, rigid aluminum has the strength of metal without the rust printed surface has clear uv protective overcoat to withstand splashes, washdowns, and outdoor conditions, plus abrasion and chemical resistance rounded corners and 3/16 mounting holes for installation.