This reservoir drain cap (part number WP2185696) is for ice makers.
Reservoir drain cap WP2185696 covers the reservoir drain port opening.
Follow the instructions in your owner's manual when replacing this part.
WP2185696 (or 2185696)
The manufacturer substituted part 2185696 with this new part WP2185696
Refrigerators and Freezers
1.25" INHx 1.25" INHx 0.5"FOT