MP Meter Pak meter centers offer a wide range of multimetering applications. The 9 inch meter center spacing allows for more sockets per device. This creates lighter and more compact branch enclosures. Four meter socket configurations are available with options such as ring or ringless, 4 and 5 jaw, horn or lever, and jaw release. This is a secondary surge arrester mounting kit for Meter-pak meter centers. MP meter centers have UL Listed indoor rainproof NEMA Type 3R construction which meets EUSERC standards.