BK/GBB-20-R is a 20-ampere very-fast acting ceramic tube fuse designed for circuit protection in AC and DC applications. The fuse features a 1/4" x 1 1/4" (6.3 x 32 mm) ceramic tube body with nickel-plated brass endcaps and is rated for 250Vac and 125Vdc operation. It provides an AC interrupting rating of 200 amps at 250Vac and 200 amps at 125Vac, with a DC interrupting rating of 200 amps at 125Vdc, and exhibits a typical cold resistance of 0.00330 O and voltage drop of 0.0728 V at rated current. The fuse meets UL standard 248-14 and is UL Recognized for ratings 1-30A, making it suitable for industrial control systems, power distribution equipment, and electronic device protection where fast response to overcurrent conditions is required.