ZCASE® SMZ Stud Mount Fuse Holders Littelfuse ZCASE® SMZ Stud Mount Fuse Holders allow users to mount fusing to an M8 or M10 stud on batteries, alternators, battery switches, and electrical relays. SMZ Fuse Holders accept Littelfuse ZCASE fuses with 40A to 600A ratings. The SMZ series is ideal for stacking to create a 2- and 3-circuit version. A standard M8 or M10 nut can secure the fuse holder to a stud. The fuse holder is available in four configurations, each with a red protective cover designed to reduce the risk of accidental contact with the fuse or battery terminal.