Source google image: https://sc01.alicdn.com/kf/HTB1Qkc5SXXXXXbuXpXXq6xXFXXXG/3-phase-20a-waterproof-isolator-switch.jpg
B and q isolation switch
Source google image: https://sc01.alicdn.com/kf/HTB1Qkc5SXXXXXbuXpXXq6xXFXXXG/3-phase-20a-waterproof-isolator-switch.jpg