TEST REAGENT Kit is a basic and simple test to check the quality of your water. Can be used for checking: - Your tap water - Filtration of your water filter - Quality of your water - Indicator of when filter requires replacing - Chlorine amount present in water. This may be useful for seeing when your filters are getting exhausted or how strong the chlorine content actually is in your source water. It is easy: just add 2 drops to about 30ml of water and see which colour develops. With the Chlorine testing drops you can assess the amount of chlorine present in water. Otherwise compare the resulting colour reaction with the colour chart showing below. The concentration of chlorine is nominated underneath the resulting colour, for example: ochre = 2ppm Combine with another item the buyer has paid shipping on. It's free if it fits with the satchel. Bubble Wrap is available via Option #2 For bulk buying, choose Option #3 $14.99 option. Thank you