Gascem doorknob lockout device operates by disabling the turning feature of handles of certain design and dimension eg door knob. Designed like a clamshell, it snaps shut around a handle before locking up with a padlock (padlock not included). Can't turn the door knob, access denied it is that simple! And it is also your door knob lock without drilling! The lockout devices simplicity belies its wide and versatile functionality from the obvious of door knob & door handle lock for kid safety or dementia patients, to outdoor faucet lock, valves for gas tank, propane tank, spigot wheels, and more! The lockout device is hardy, made of quality steel, powder coated for protection against corrosion and rust. Gascem Lockout Device is ONLY for handle design of CYLINDRICAL KNOB AND HANDWHEEL (BUT NOT LEVER OR CROSS). And, also for handles of suitable dimension. PLEASE CHECK YOUR HANDLES DESIGN & DIMENSION AGAINST THOSE IN THE PHOTOS ON THE LEFT OR DESCRIPTION BELOW BEFORE ORDERING