Special roach control device that contains Gentrol Insect Growth Regulator hydroprene for 90-day control of roaches and other stored product pests. Activating Gentrol Point Source is as simple as squeezing the raised end of the plastic, adhesive-back device. This releases Gentrol IGR onto a filter paper. From there, it moves up to 75 square feet, damaging adult roaches and preventing them from reproducing. 20 units per box. Gentrol will not kill roaches, it only prevents them from reproducing.