Certain electrical and control systems require protection by fuses. CSFL4U have a specially designed space for cartridge type glass fuse and accept Ø5 x 20 or Ø5 x 25 mm fuses. CAFL4U accepts Ø1/4 x 1-1/4 in. fuses. The fuse can be engaged or disengaged by the movement of the carrier. CAFL4U(L) is equipped with a LED for blown fuse indication.