CHM1DIU 30A Rail Mount Fuse Holder With Indicator for 10 x 38mm Fuse. This range of fuse holders are also known as finger-safe fuse holders, originally created and designed to be used with Class CC, supplemental and PV fuses. These type of fuse holders will predominantly be found within industrial and commercial environments. The rail mount fuse holders contain fuses that are slotted into sets with metal contacts.