Our Colloidal silver contains pure, medical grade silver, which has been used for many centuries. It is produced using electro-controlled technology & pure water from a 9-stage water purification process, to achieve a very small particle size (0.0006 to 0.005 microns). This small particle size is important because it provides a much greater surface area & therefore more of an effective liquid. The 15ml refillable size is ideal for carrying in a bag or pocket. Use the 200ml non-spray-nozzle size to refill the 15ml & 100ml spray-nozzle sizes. This product has remained exactly the same for many years & continues to be colloidal silver of the highest purity & quality Vegetarian & vegan friendly. Colloidal Silver containing 99.99% pure silver, free from heavy metal contamination. Contains very small particle size (0.0006 to 0.005 microns) for enhanced contact with bacteria Ideal for use all-round the house & perfect for travel Use the 200 ml non-spray nozzle to refill the 15 ml & 100 ml spray-nozzle sizes