This is a normally closed relay wired into a single red wire.
When an earth is supplied to the yellow wire the relay will open and break the contact to open the circuit wire.
Often used to cut the ignition or 12V feed to a device.
Special relay to mute audio when reversing to allow parking tones to be heard clearly.
This relay is designed for aftermarket radio fittings where a parking sensor retention interface has been fitted.
This relay will use a positive reverse gear signal to mute the new head unit, so when the car is reversing the radio is silent and the parking tone interface can be heard clearly.