X084315P 12.5A Ceramic Cartridge Fuse, 6.3 x 32mm. This range of miniature ceramic cartridge fuses are either ultra-rapid fuses (FF) or fast acting fuses (F) The ultra-rapid fuses operate at higher temperatures so are ideal to provide circuit protection to semiconductor devices. The fast-acting fuses are ideal to protect less sensitive components. Fast acting fuses are the most popular fuse. 6.3 x 32mm.