DPD XT Palintest Photometer Reagent Tablets, 250 - AP033/1
 
Palintest’s DPD XT tablets are designed for photometric analysis of total chlorine in pool and spa water at elevated levels

The “XT” (extended total) formulation lets you measure chlorine up to ~10 mg/L (ppm), making it ideal for post-shock testing or systems with high sanitizer levels
Use them with compatible Palintest photometers to get precise, reliable readings of combined and total chlorine concentrations