Does the job, but not fully thought out.

Overall this fuse holder is easy to use but not idiot proof. The stack of washers makes it a little unclear what order to install the eyelets and fuse in. After a couple of minutes of messing around it becomes clear what the intent was. The black base, washers etc work well enough but the clear cover has a couple of issues with it. It doesn't secure well enough with the tab locks for my tastes. So I secured the cover with a zip tie so it won't come off and get lost. The other issue is the wire openings don't even attempt to keep dirt & debris from entering the fuse holder. Some foam rubber around the wire will seal the opening and accommodate smaller wire gauge than 1/0 but is not included. It may be possible to connect 2 4 gauge wires on the same end but keep in mind the unit was designed for 1 each of 1/0 gauge wire per end so it may require the cover opening to be filed. This unit isn't perfect but can be fairly easily modified with a file and some foam rubber to seal the wire openings. Don't forget a zip tie to hold the cover on securely for under the hood installation. All fairly minor mods that make this a reliable and inexpensive unit.

Works

Haven't hooked either one up yet, but It's obvious that they do what they're meant to do. Looks like some sort of glue holding the bolts down, so I suggest not torquing these much. Strait budget piece here.