The BK/MDL-1/4-R is a 1/4 x 1 1/4 inch time-delay glass tube fuse designed for circuit protection in electrical systems. It features a 250 Vac voltage rating with an AC interrupting rating of 100 amps at 250 Vac and 10,000 amps at 125 Vac, along with a typical DC cold resistance of 0.205 O and a typical melting I²t of 86.2 A²·s. The fuse is constructed with a glass tube body and nickel-plated brass endcaps, meeting UL standard 248-14, and is available with optional axial leads and board-washable sealing. Time-delay characteristics allow it to withstand temporary current surges while providing reliable protection against sustained overcurrent conditions, making it suitable for industrial equipment, power distribution systems, and electronic circuit protection applications.