About five years ago, the 23L motorcycle tank I had became rusty, and I repeatedly cleaned it with two bottles of this product. I soaked it overnight many times, and it became quite clean, but I purchased two more bottles to thoroughly clean and rustproof it. The diluted solution is currently being used to remove rust from bicycle parts and farm tools. I have one unused bottle left, so I'm offering it for sale. This is a rust remover and rust inhibitor for gasoline tanks. It's an excellent product that can be used on most iron products, such as bolts, tools, and camping gear! Not only can it remove and prevent rust in tanks simultaneously, but it's also a great product that can be used on various iron products like pegs, tools, machetes, and axes. Moreover, it's economical because it can be diluted 10-20 times and reused. 【How to Use】 Detailed instructions for use are written on the product surface. Please follow the proper usage instructions to effectively clean the tank. 【Precautions】 Be sure to check the precautions before use and use it safely. In particular, be careful about mixing it with other chemical products.