KYOWA WGA-120A Instruction Manual page 20

Auto balance control input terminal
Power supply input terminal
Protective ground terminal
Short-circuit the AZ terminal and COM terminal 2 times within
0.5 seconds to execute the auto balance adjustment (auto balance
model only). (See "4-5 AUTO BALANCE ADJUSTMENT.")
Power supply terminal.
Power supply varies with WGA-120A models. Carefully read
the Specifications before connecting the power supply.
GND terminal. Be sure to connect the product to the ground
before turning ON the power.
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