Smith-Blair Steel Couplings offer many distinct advantages when installed in a piping system. Properly selected and installed, flexible couplings maintain the continuity of the pipe system, retain the line contents under internal pressure, and prevent infiltration under vacuum. The 411 Series has several advantages including: no special pipe end preparation required, simple installation requires only a wrench, pipe does not have to be cut to exact length, exact alignment of pipe ends is not necessary. Coupling fits on outside wall of pipe so there are no internal projections to disturb flow and no damage to the pipe lining. Many types of pipe, including pipes of different materials, can be joined.