BK1/S505H-1-R is a time-delay 5×20 mm ceramic tube fuse designed for 250 Vac / 400 Vdc applications with a 1 A nominal current rating. The fuse features a ceramic tube construction with electroplated end caps and provides a high breaking capacity of 1500 A at maximum voltage, with a typical DC cold resistance of 0.14 O and I²t rating of 153 A²s. It is designed to IEC 60127-2 standard and is RoHS compliant, lead-free, and halogen-free, with optional axial leads available. The fuse is commonly used in power supplies, adapters, desktops, notebooks, televisions, displays, set-top boxes, lighting ballasts, battery chargers, printers, game systems, and air conditioning units, offering reliable overcurrent protection across a wide range of consumer and industrial applications.