The Renogy MC4 In-Line Fuse and Holder works like a charm. The inline fuse just snaps in place on the positive line. I also like the ability to quickly disconnect it by pushing in the little tabs if needed. To replace the fuse, just pull and twist the holder apart. Fuses are important to add to the wires and this one works well, so I highly recommend it.
This is my second purchase of solar panels. Very dependable. The first one I bought rode in the back seat of my truck for almost 160 miles of washboards , washouts and rocks. Wired up the panel and it has been working as expected since Oct 2018.