Constructed from tough anodized aluminum, with a tamper-proof locking tab, these hasps are impossible to remove while locks are in place. Front and back of hasps contain write-on surfaces that accept pencil, pen, or permanent marker. Pen and pencil markings can be easily erased too, allowing for repeated use. Each hasp has six lock holes (5/16" Dia) and reads ?DANGER DO NOT OPERATE ... ETC? (front) and ?DANGER ? This energy source has to be LOCKED OUT ... ETC? (back). 7 1/16"H x 3"W x 3/16"D. Red. 5/Pkg.