Middle Atlantic MPR-JB843A Junction BoxDesigned for professional AV installations, the Middle Atlantic MPR JB843A Junction Box delivers dependable cable management and durable protection for power and signal runs along MPR raceways. Built from sturdy steel and finished in a black powder coat, this junction box stands up to the demands of busy control rooms, studios, conference facilities, and high traffic environments. Its rugged construction, pre punched electrical knockouts, and seamless