The entire package includes 4 plastic bottles. One bottle should last for descaling. I have cleaned the Cromargol Entkalker a Saeco coffee machine. The water softener to the water tank, with water up to the max. Filled mark and can go through the program. By doing without a program, you should have run through the coffee machine 2 times with clean water after decalcification. This is also in the included instructions for use of means. The instruction manual is short, but perfectly adequate. Already after the first treatment, you can see the success in the emerging water. Also, there are no unpleasant odor, which I had already times when descaling. If the descaling something splashing comes to the coffee machine, or the surrounding surfaces, easily removed with a damp cloth. Then you can be sure that there are no stains. Moreover, one should be very careful that you not get in eyes. But a relevant safety label is located in the instructions.