This is a part of the Schurter Fuse Line, specifically the 1241.1022 Ceramic Fuse with 4 Ampere breaking capacity, 250VAC working voltage, and 5 x 20mm size. This fast acting fuse is UL recognition, CSA listed, and RoHS compliant. It also includes a time-lag/slow blow feature to allow for greater protection in certain conditions. It could be used in multiple applications such as power supplies, communications equipment, industrial automation equipment, and more.