Use the Avantco 178HINGSSHL middle left door hinge as a direct replacement for the one that came on your Avantco SS-4 half door refrigeration unit. This hinge attaches to the middle left side of your unit, between the top and bottom half doors. Working hinges allow the doors of your unit to open and close smoothly, keeping the cold air inside keeping the cold air inside and maintaining food-safe temperatures. Replace a damaged hinge right away so that your unit continues to run efficiently.