No, they're for fresh water.
Purigen = Seachem Purigen It's a filter media that you place in bags:
http://www.seachem.com/Products/product_pages/Purigen.html
Mat = Filter mat It works kind of like filter floss, but it comes in large mats that you cut to fit as you need:
http://cgi.ebay.com.my/Aquarium-Fish-Tank-Filter-Mat-Wool-Sponge-Foam-90x30cm-/180504734643
Purigen = Seachem Purigen It's a filter media that you place in bags:
http://www.seachem.com/Products/product_pages/Purigen.html
Mat = Filter mat It works kind of like filter floss, but it comes in large mats that you cut to fit as you need:
http://cgi.ebay.com.my/Aquarium-Fish-Tank-Filter-Mat-Wool-Sponge-Foam-90x30cm-/180504734643