Mazda Relay, B5B4. This relay is in good used condition and is a genuine OEM Mazda part, not the cheap aftermarket stuff. This relay has been thoroughly tested here at our facility and is in good working order. We test each relay to make sure the "door" opens and closes, we also test for resistance on the coil. These relays typically outlast a vehicle, however, when one fails our buyers can count on us to deliver a good relay for a fraction of dealer replacement cost. We offer free shipping on this item and a 6 month warranty.