Just thought I would mention that I am using a 30A water heater switch from HD for my HLT. Looks like a wall switch, am using it to manually heat my HLT 4500 element.
If I can offer a suggestion: Throw some panel tags on the control panel so that everyone else can see what those pretty lights and switches are for. They're pretty cheap in the grand scheme of things and will also make the panel safer to use even for yourself. Most of us don't brew every day and it's easy to forget sometimes which switch is for what. You can also use a label maker if you have one available for even less expensive tags (but I find they tend to peel after years of use).
Close!! It's actually a mounting kit for a Cisco Aironet Wireless Access Point. I'm a computer engineer, so I get some awesome leftovers when building development Datacenters and such!