It's your it's door seal. It has a coil inside that stays warm so it doesn't freeze to the frame of the fridge. Also if your having trouble keeping the same temp inside check your fan in the back and make sure it's turning and not turn at a slow speed of it is them it needs replaced. It keeps those hot coils cooled down while the compressor is creating a freezing reaction the the copper coil on inside of freezer and the fridge part. If the coil on the back are dusty and dirty take it and clean them with a vacuum and a paint brush or a broom then suck up the dirt off them. I hope this will help you guys understand...Take care/:) Godbless you!

You'll need to download a real term wrapper and then go from there....hope that helps