The dispenser holds up to 90 tampons. This means that it takes a long time before it empties completely and usually you will be able to see when it is running low. With that said, you do not need a dispenser in every bathroom. Employees, students and guests will quickly learn which bathrooms have tampons.
Most clients decide the number and placement based on how the property looks, how many employees they have, students or guests should not have to leave one side of the building to the other to get hold of tampon. We usually recommend that you place an automatic next to the most used toilet groups or one automatic per floor/department. You can also clarify which toilet redlock is available through a nice red sign on the toilet door that can be ordered as an additional product.