WET Inc., of Carol Stream, Ill., presents its DPD powder pillows that are designed to provide many benefits over the standard tablets and bulk powder. Some of the benefits include their convenience (they dissolve easily without crushing), increased accuracy (the fast rate of dissolution minimizes the positive interference of the combined chlorine on the free chlorine test), longer shelf life (they’re unaffected by environmental elements such as light and moisture), and integrity (they’re protected against cross contamination).