Manhole Barrier Device prevents terrorists, thieves and other unauthorized individuals from entering underground tunnels via manholes. Protects underground infrastructure and utility lines for telecommunications, water, gas, electricity and multiple systems. Consists of a self-contained stainless steel barrier that sits directly on flange beneath manhole cover. Blocks entire manhole from unauthorized or unlawful entry, even if manhole cover is missing. Creates an impenetrable shield that is nearly impossible to saw through or bend. Features spring lock, along with a coded key that comes in both a manual T-wrench and a high-speed drill attachment. Comes in diameters ranging from less than 32 ins. to more than 44 ins., as well as custom sizes. Weighs about 35 lbs., depending on diameter. Can be installed by one worker in less than 5 minutes, without requiring special tools. Authorized worker can unlock and remove device in 30 seconds for fast access to manhole. Manhole Barrier Security Systems Inc., Garden City, N.Y.