GSB – C2
(Country Side)
Low level of pollution, rural environment, urban area and moderate industrial atmosphere
(low)

GSB – C3
(Industrial)
Large city, industrial atmosphere, coastal regions with moderate salt content
(moderate)

GSB – C4
(Sea Proof)
Coast with medium level of salt content
(high)

GSB – C5
(Sea Proof Plus)
Coast with high level of salt content, open ocean
(very high)