This is a set for the so-called "Midbon" system, which allows you to easily and inexpensively make carbonated water at home. You can make it for about 10-13 yen per liter. When I made it strong, my child said, "It's too spicy to drink," so I was able to make strong carbonation. Please adjust the strength to your liking. In addition to the cylinder's main valve and the pressure reducer's dial, a valve is also installed in the middle of the hose, making continuous production easy. As shown in the image, it is a set of a pressure reducer for draft beer & highballs, hoses, and two caps. The pressure reducer is the 4.0 type, which has a higher gas pressure. Other items needed besides this set are: - Carbon dioxide gas cylinder (Midbon) - Empty plastic bottles for carbonation - Cold water - A tool that can tighten a 30mm nut You can probably buy a 5kg carbon dioxide gas cylinder at a liquor store in your neighborhood. I purchased mine at the chain store [Yamaya]. I will sell the working item that I was using until recently. Since it is a used item, there is a feeling of use. There is rust on the valve inside the plastic bottle cap, but I was using it in this condition. Please search the web for more information on how to make it. Since I am an amateur seller, there may be oversights. Please check the images carefully and purchase after you are satisfied. The images may not fully represent the condition of the product, but this is a sale of the actual item in its current condition. Please refrain from purchasing if you are a perfectionist or are looking for an extremely high-quality item. This item has been in someone's possession once, so we are looking forward to your purchase if you understand. After simple packaging, we will ship via anonymous 60-size delivery. If you have any requests regarding delivery date or time, please let us know in the comment section after purchase, and we will do our best to accommodate you. Thank you.