Use this Orbit 1/2 in. x 2-1/2 in. Cut-Off Riser Extension to position sprinkler heads at the appropriate height for your application. The riser extension is designed to be easily cut to suit the exact requirements of your sprinkler system. This riser is an extension to the cut-off riser and is made of flexible plastic composition that allows constant bending without breaking. It can be cut to the desired length and is not for use under continuous pressure.