BK/GMA-4-R is a 4A fast-acting glass tube fuse designed for circuit protection in 125Vac applications. This 5×20mm fuse features a typical DC cold resistance of 0.026O and a maximum voltage drop of 205mV at rated current, with a pre-arc voltage of 19V. The fuse operates with an interrupting rating of 10,000A at 125Vac and exhibits fast-acting characteristics with a 2-minute maximum opening time at 200% of rated current. It is UL recognized (Guide JDYX2, File E19180) and PSA approved, making it suitable for industrial and consumer electronics requiring reliable overcurrent protection.