Screen wedge made out of black lexan. Fits Value Nozzles. Precision cut to perfect 90 degrees, ideal for mounting adjustable nozzles in screen vivarium tops (ie. chameleon enclosures). Protected by a peelable adhesive label. 1/2″ hole drilled in the middle. To install a nozzle, just poke a hole in your screen, put the wedge on top of the screen and mount the nozzle. Makes misting system installation in screen cages a breeze.