For a clean toilet without using harsh cleaners, try our 2000 Flush Natural Loo Cleaner! It's so easy to use - just drop it into your cistern and let it do the work! The blue tinted water indicates the cleaner is hard at work cleaning, sanitising and deodorising for up to 2000 flushes. You know it's time for a replacement when it no long flushes in blue. Helps eliminate uric acid salts, limescale, mildew and soils. Measures 7cm by 5.8cm (2-3/4" by 2-1/4").