The R-2500 CHEMets ampoules are a refill for K-2504, K-2504A, K-2504B, K-2504C, and K-2504D chlorine test kits. When purchased with A-0171 it is also a refill for K-5808 and K-5816 chlorine dioxide test kits. It contains 30 self-filling CHEMets ampoules packaged securely in cardboard trays and box. Notice: Due to a recent change R-2509, R-2504, and R-5808 are no longer available. Direct equivalents are: R-2509 is replaced by R-2500 and A-0171 R-2504 is replaced by R-2500 R-5808 is replaced by R-2500 and A-0171 Analysis Time: 1 minute