Solid steel U-bolt hasp with malleable steel lock plate provides maximum security|7/16 x 3/8 in hole accommodates up to 9-3/8 in shackle locks|Locks switch in either on or off position|Installs quickly using existing plate screws|The Wall Switch Lockouts feature a tamper-proof design that protects against vandalism and accidental breakage|Hinges for both Universal and Standard design open for unobstructed normal switch operation