If it says 120ml, it's wrong, it's 1000ml and I believe having tried other branded ones, that it is the most effective, with the best quality-price ratio. For tough issues with salts, I would suggest a larger dose (1 to 5 instead of 1 to 10 as they say. For example, for 500 ml of water for the espresso machine, 100ml of the product.

My coffee maker is brand new and I used it for a month now. It showed that it does the job! Where it clearly appeared reliable was in an old kettle of my husband's that he hadn't cleaned for... years. Very good product!

It really does the job. I didn't expect it. My espresso machine was completely clogged. Two drops were dripping in the sink and on the counter. I hoped that by using this descaler it would drip a little more so that I could make two decent coffees until I get a new coffee maker. As soon as I started the cleaning process, the coffee maker began to transform. Now I have a coffee maker that looks like it was bought yesterday. Because it doesn't have instructions, I will describe the process to you.
Fill the water tank of your coffee maker, mix in about four or five caps of this product, heat the coffee maker and let it run until all the water is finished. Of course, place a small basin underneath for the water. Repeat the process about three times. Just heat the water every time you refill the water tank. When you finish these three flushes, fill it with plain water and repeat three more times until the internal pipes are fully cleaned from the residues of the cleaner. Anyway, even if there are residues left in the pipes, the product is organic, you won't get anything. Prefer this product instead of the cleaners sold in tablets or liquid form. The cleaner didn't work for me. Only the descaler really worked.