Taylor Technologies powder swimming pool test reagent R-0870, DPD Powder. For use as directed with Taylor Technologies test kits. R-0870 is used in combination with R-0871 and R-0003 for the Free & Combined Chlorine (FAS-DPD) test. 10 gram vial with dipper spoon. This listing is for a 2 pack of R8790I DPD Powder 10 gram each