【5.1" / 5" Universal】: When you want to replace the original portable AC hose, the index you need to pay attention to is not the brand, but the diameter and the thread direction of the hose. Generally, the diameters are divided into 5.1 (5) inch and 5.9 (6) inch , and the thread is divided into clockwise and counterclockwise (Refer to Figure 3 for Judgment Method), so you can select the correct AC hose!