The BK/ABC-20-R is a fast-acting ceramic tube fuse designed for circuit protection in electronic applications. It features a 20A ampere rating with 250V AC and 125V DC voltage ratings, housed in a 1/4" x 1-1/4" (6.3mm x 32mm) ceramic tube with nickel-plated brass endcaps. The fuse exhibits fast-acting characteristics with opening times of 4 hours minimum at 110% of rated current, 60 minutes maximum at 135%, and 120 seconds maximum at 200%, providing reliable overcurrent protection. With a typical DC cold resistance of 0.00366 ohms and a typical melting I²t of 550.8, this fuse meets UL standard 248-14 and is suitable for industrial control systems, power distribution equipment, and electronic circuit protection where fast response to overcurrent conditions is required.