Received one unit cracked but it was replaced without trouble, second unit was just fine. Was a little hard to spot the crack since its clear, definitely check yours out after it arrives.

The SW FHXL0 isn't 100% sealed, on the ends there is some play between the metal and the plastic screw-on lid, but it could probably be totally sealed pretty easily. It's an extremely small gap and its only present when the metal inside piece flops around ever so slightly.

The XB-MFBU has adaptors for other wire sizes and the connections can be angled, but it has a sizable gap around the fuse chamber so it's definitely not sealed. Going with some of the StreetWires instead just for the better seal.

p.s. note re: other review, the set screw does have teeth on the rim now, but the center is still concaved. But I doubt it matters since the walls are all metal, the set screw is only 2% of what's making contact with the wire.

Got this in the StreetWires 1/0 kit. Feels solid, and heavy. 1/0g fits perfectly in these, but I wish the set screws had the "teeth" or we're rounded off that the end, to make a better connect. Overall, I love it, but for the price by itself, I'd ask around local shops first.