BK/MDL-1-1/4-R is a time-delay glass tube fuse designed for circuit protection in electrical systems. It features a 1/4 x 1 1/4 inch (6.4 x 31.7 mm) physical size with nickel-plated brass endcaps and is rated for 250 Vac with an AC interrupting rating of 100 amps at 250 Vac and 10,000 amps at 125 Vac. The fuse exhibits time-delay characteristics with a typical DC cold resistance of 0.205 O and a typical melting I²t of 86.2 A²·s, providing reliable protection against overcurrent conditions while minimizing nuisance trips. It meets UL standard 248-14 and is RoHS compliant, making it suitable for industrial control systems, power distribution equipment, and general circuit protection applications where selective coordination and thermal stability are required.