10 year guarantee my arris, that will only cover the basic structure of the thing, i.e for cracked housing etc. no way in hell they will cover the moving parts / seals.
why not try an ibox shower housing
30lpm showers. a bit excessive don't you think?
why not fit flow limiters to the showers and save the environment, new builds are designed around 125 litres per person per day. One of you showers uses that in less than 4 minutes.