GS is a voluntary safety certification mark for technical equipment and is widely
recognized in EU. It means the product is tested and complies with the German
Product Safety Act (a.k.a. ProdSG), if available, European safety requirements for
such devices. The certificate only be issued by an accredited laboratory and followed
by periodic factory inspections covering the quality system for the product’s
production.
The GS mark, although not required by law, can make a great difference in cases
where a product’s malfunction leads to an accident for which its manufacturer
could be held responsible under Germany’s (and the EU’s) strict product liability
laws. GS mark symbol is different from lab, as lab name is add besides the GS
mark, below is a general GS mark and a lab GS mark.