This door hinge spring (part number 5304503731) is for microwaves.

Door hinge spring 5304503731 applies tension to the door hinge to prevent the bottom-hinged microwave door from dropping open too quickly.

A service technician should install this door part because the door contains shielding components. The technician must correctly test the microwave for leaks in the microwave shield before you can safely use the microwave.