Need help to identify what fell off my RAV4

[JakeRav4]

Hi,

Was driving my 2005 RAV4 XT3 when something fell off the left side of the car from underneath. I had the windows down and could hear a slight tinny noise like a rattle that I assumed was coming from the exhaust. The next thing I know it sounded like I was dragging something and then it came off. I pulled over and retrieved it but am unsure where this has come from. I have attached photos of it. It is extremely light but wandered if this is off the brake system.The car seems fine and brakes fine with no pulling left or right and hand brake holds. I am going to take it to a garage but wanted to know if anyone could shed some light on it so I know what I am talking about when I take the car in.

[FROSTYBALLS]

Back plate off one of the brake discs?

[JakeRav4]

That's what I was thinking. From the sound I heard it cam from front left side. The piece is in pretty bad condition and the car was MOT'd in March. I would have thought that would have been picked up :(.

[JakeRav4]

After doing lots of research I am 95% sure its the brake dust shield that has rusted through. Will check which one tomorrow when its light. Many thanks again FROSTY, now just need to solve the beeping and I am set :).