Blind Flange Lockout Device, Color Red/Black/Silver, Nut Dia. 1.000 in to 1.875 in, Fits Pipe Size 3-1/2 in to 12 in, Flange Size 3-3/4 in to 10-3/4 in, Max. Number of Padlocks 4, Padlock Shackle Max. Dia. 5/16 in, Material Aluminum/Steel, For Use With Pipelines, Standards OSHA 1910.147