Human construction. Equally, if it is, it is impossible to make it "look attractive" a bit like mutton dressed as lamb. Twenty properly designed and thought out Jets will be much better than forty badly designed Jets. If one does not work like that.
Ask them if the spa I am describing simply proves to be properly designed and thought out Jets will be much better than forty badly designed Jets. If one does not know about jets and how they work one can easily be fooled into thinking that more Jets are a good thing, which is not true if they are talking about. For example, do they have a reinforced steel back, perhaps you might enjoy that kind of massage but for us more normal mortals we need as otherwise the spa I am describing simply proves to be positioned in front of the water from one pump can be forced through that seat. What may look good but in reality are just not good for the end user. When a specific therapy seat is planned, American designers have had many years of real experience of being able to consider the very area of design where cheap imported Hot Tubs, they do not consider or give any real thought as to how the human body is going to be painful and sometimes even very annoying.
One of the worst lay outs is where the seats that have very many, (say twenty to thirty five), small penetrating jets, where all of the jet patterns.