The PJ III is the workhorse of the PolyJohn line. The traditional design makes it ideal for a variety of applications. And the PJ III is built to last. The unit is manufactured with our proven, specially formulated high-density polyethylene. This three-part formula developed and tested in coordination with Ciba-Giegy and Phillips 66 has been proven to extend the life of our portable toilets to over ten years. This special polyethylene is resilient, impact resistant and stands up to weather extremes.