JED Pool Pool And Spa Test Kit Refills provide an essential solution for maintaining the balance in your pool or spa water. This refill set includes 1/2 oz. bottles of OTO and Phenol Red, which are crucial for accurately testing chlorine and pH levels. Designed for convenience, each package contains one bottle of each chemical, making it easy to replenish your existing test kit and ensure reliable water quality monitoring. The compact bottle size allows for easy storage and handling, helping you keep your pool or spa safe and clean with minimal effort. Model Number: 00-230