Certificate of qualification to execute Public Works (SOA) for the following categories and classes: Cat. OG1 class. III Cat. OG3 class. V Cat. OG6 class. IV Cat. OG7 class. V Cat. OG8 class. IV Cat. OG10 class. III Cat. OS1 class. II Cat. OS21 class. III Cat. OS24 class. II Quality management certificate : UNI EN ISO 9001:2008