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The main advice is to work with a local solutions provider where possible, for knowledgeable, trained installation and maintenance support, who have links back to the manufacturer of the products used.
It is useful, however, to gain a basic understanding of products and design independent of the suppliers so the following links are provided to manufacturer web sites on the Internet. All these manufacturers work with a large network of dealers around the world (local solutions providers) to sell and distribute products though they can and do sell directly through their web sites.