Brady's Universal Fuse Lockout device has been designed to prevent the un-intended re-energization of an energy source through a fuse. This device is extremely easy to use. Just clamp onto the fuse holders and use a small flathead screwdriver to tighten the set screw in the device, then place a padlock though the hole to prevent access to the set screw fits most fuses holders between 20 Amps and 400 Amps. This easy to use new device creates a more universal approach to locking out your fuses.