This Avantco 178CAPTUBE40 0.04" capillary tubing is a direct replacement for the one that came with your Avantco refrigeration unit. It helps control the flow of refrigerant in your unit and connects the remote bulb to the thermostatic expansion valve. If your capillary tubing is worn or broken, use this replacement so your unit can get back to operating efficiently. This capillary tubing features a 0.04" diameter and is sold in inch increments. Refer to the manufacturer's service manual or the compatibility sheet to determine the length of capillary tube needed.