The Test Strips designed for FROG @ease Sanitizing Systems. With a technology as unique as FROG @ease, it only makes sense it would have a unique test strip.  FROG @ease test strips let you know when your SmartChlor® Cartridge is empty. There is no need to measure the level of chlorine because it self regulates at the same level every time. Instead the single color on the bottle tells you your cartridge life is fine or you need to replace it.