Siemens SIMATIC V2 Operating Instructions Manual page 134

Markings and symbols
B.1 Safety-relevant symbols
Symbol Meaning
Only for industrial applications and indoor areas (control cabinet)
Device is to be integrated or installed in a control cabinet
Integrate or install devices approved for Ex Zone 2 in a control cabinet
with at least IP54
Integrate or install devices approved for Ex Zone 22 in a control cabinet
with at least IP6x
134
Reference
IFP V2, IFP V2 PRO, IFP V2 ETH
Operating Instructions, 03/2023, A5E46641410-AE