Hard Shingles with Metal Clip - HELP!

My wife and I just got back from Switzerland and are looking for a product we saw in the mountains. I have seen these in several places but the pictures we took of the house with these clips was in Apenzell, specifically near Wassauren and Ebenalp.

What we are looking for are shingles for a house. They are hard, plastic-like (or maybe a synthetic substance) shingles for the outside or a house or hut. They are for vertical surfaces like walls (they may work on a roof as well but that is not how I saw them). The color I saw was sort of an off-white almost green gray yellowy. They are held in place by a metal clip that hooks underneath the shingle and runs up behind it.

I have posted a photo of the shingles from the Ebenalp cablecar station which uses them on Flickr:

Photo of Shingle on Flickr:

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We appreciate any help at all in finding out what they are made of, who makes them (or shingles like them), and whether we can buy/import them in the states or whether we will have to order them in Switzerland and ship (ugh!) them back to the states.

Thanks in advance--so much!

Richard