FSPDBs introduce a new level of safety and ease for installing power distribution blocks. An IP20 level of finger safe protection is achieved using the FSPDBs and thus eliminates the need for special covers or custom Plexiglas sheets to protect your panels. FSPDBs (sizes 1 to 4) simply snap onto 35mm DIN rail to provide the quickest installation. And since they are modular, you can form any number of poles desired. If multi-pole panel mounting is desired, multiple-pole assembly pins are available. FSPDBs provide a safe, convenient way of splicing cables, splitting primary power into a variety of secondary circuits or providing a fixed junction tap-off point. size 1 cap .