The Unison DR12 120V dimming rack is a great solution for lighting control. However, please note that it doesn't come with a key to lock the door.

Using this 120V ETC Unison DR12 dimming rack is easy. Just connect it to your lighting system as per the wiring diagram. When using, make sure the power supply is stable. As for the known issue, since it doesn't have a key to lock the door, you may need to source one separately if you want to secure it. For maintenance, keep it in a dry and clean place. Regularly check the connections to ensure they are tight and there are no signs of damage. If you notice any problems, stop using it immediately and seek professional help.