RG59/U, RG62/U, RG210. Bulkhead Jacks: Versions are available for front mounting (F/M), rear mounting (R/M) , crimp types, bulkhead mount grounded, or bulkhead mount isolated. These jacks are held into the panel by a hex-nut and lock washer. All units feature nickel plated, brass bodies, and gold plated phosphor bronze contacts.