This Din-Rail Adapter, Provides Quick Mounting For All Mersen 303 Series Midget and Class CC Fuse Blocks to All Symmetrical 35MM Din-Rail or Asymmetrical 32MM "G" Rail. An Adapter Is Attached to Each Pole With The Screw Provided. Its Molded Of Black Polycarbonate and Is Mounted or Dismounted From The Rail Simply By Depressing The Finger Pull