The BK/HTB-42I is a panel-mount fuse holder designed to accommodate both 1/4" x 1 1/4" and 5 x 20mm fuses, featuring a front hex nut mounting configuration. This holder is rated for 250V and supports a maximum panel thickness of 0.30 inches (7.62 mm), with a knob-type carrier length of 1.69 inches (42.9 mm) plus in-line terminal. The device is constructed from high-temperature, flame-retardant thermoplastic material that meets UL 94V0 standards and withstands 15 to 20 Lb-In torque to the mounting nut. It is UL recognized (IZLT2, E14853) and CSA component accepted (Class 6225-01, File 47235), ensuring compliance with major safety standards. The BK/HTB-42I is ideal for industrial control panels, power distribution systems, and equipment requiring reliable fuse protection with flexible carrier options.