This professional silver cleaning solution is used by precious metal manufacturing factories, workshops, and artisans in Europe, the home of silver product manufacturing, as well as for cleaning silverware in top-class hotels. The reasons for its popularity are that it can be used repeatedly (until the solution runs out), it cleans well, and it's inexpensive. I have a lot of silver products, so I bought several bottles at once. However, since it can be used repeatedly even when it gets dirty, I'm decluttering the unused portion. The usage instructions are on the label, but it's a remarkable product that removes tarnish simply by soaking the item for a few seconds and rinsing with water. In addition to silver, it also cleans 18K gold and platinum that doesn't tarnish, thanks to the surfactants it contains, making it useful for cleaning all precious metals. It lasts a long time and the cleaning effect doesn't diminish, so the cost performance is excellent. It's a British product, used for hundreds of years by professionals in European countries, the home of silver products. The price is for a set of two, and it is not sold individually.