We are pleased to announce that ZEBRA Environmental is now installing 2” ID Prepacks. With the increase in strength of our fleet of Geoprobe series 7700 & 6600’s coupled with the availability of larger diamter casing placing the 2” ID Prepack monitoring and injection wells is a viable alternative to conventional drilling. Here is why more ground water professionals are using Prepack Wells? Well Screens designed for setting Small Diameter Monitoring Wells. Pre-pack well screens are available in two outside diameters? 35 mm OD (12 or 20 mm ID) and 62 mm OD (25 or 37 mm ID).