Fences topped by barb wire remains a common installation at power plants, police stations, correctional facilities, and other venues needing high security. For fences that use 2-1/2" posts and 1-5/8" rails, look no further than this steel 3 strand barb arm, available here at America's Fence Store. Fitting atop your post, with a circular hole to accommodate your fence rails, this arm has been fabricated with an angular build. This way, the barb wires project outward from the top of the fence, making it even more difficult for intruders and/or inmates to climb over. (As does the additional fence height provided by this fitting.) Three notches built into the arm secure the wires in place, and the arm's galvanized steel build provides superior rust resistance.