This 30mL Stop Bath Indicator Kit from Flic Film indicates when the bath is exhausted and no longer effective. The use of a stop bath neutralizes the developer which sets the development time, prolonging the life of the fixer.
This kit contains a spoon for testing your stop bath. Only two drops are needed in the spoon. If the stop bath turns yellow, it's still good to use. If it turns clear of purple, the stop bath is expired.
UPC: 876578001219