Use Lovibond DPD No.3 Tablets to test the Total Chlorine levels in your Swimming Pool, Spa or Hot Tub. The Lovibond DPD No 3 tablets must be used together with the Lovibond DPD No.1 tablets to get the total chlorine reading. With a test kit the difference you get between the two values will give you a combined Chlorine (Chloramine) or Bromine (Bromamine) value. With the new blister strip, the user just pushes the tablet through the protective foil, straight into the sample. Simple, time-saving and practical.This type of packaging, long established in pharmaceutical applications, combines all the advantages of protective foil, with convenience for the user. Each tablet is contained within an individually formed foil cup, lined with the latest aluminium composite material, and guaranteeing product performance. All Lovibond Test Tablets have a minimum of 5 years before their expiration date. The box contains 100 tablets.