Latching solenoid only draws power when it opens or closes, and does not draw power when it remains in the same state. It’s sometimes called bistable solenoid. Applying a positive voltage opens the solenoid valve, and reversing the polarity closes the valve. The coil on the solenoid typically has very low resistance (a few ohms) so it momentarily draws a high current, often up to a few amps. You are supposed to only apply an impulse voltage instead of continuous voltage, otherwise it can quickly burn the coil or short the power supply.