During an installation or service dirt, moisture, or debris could enter into the air conditioning system hoses. This causes system contamination and could damage system components as well. Forget trying to put a piece of tape over the end of the hose, tape falls off the barrier hose easily. If you use more aggressive tape it can leave adhesive residue. Tape that comes off allows dirt and contaminants to enter the hose, adhesive residue means cutting more off the end of the hose to get the proper crimp for fittings. Think wrapping more tape around the outside will be better, or how about a rubber cap over the hose? Not if you're running the hoses into tight areas, that extra diameter can lead to issues routing all necessary hoses where they are needed or through what is needed (body panels, firewalls, plastic housings, etc.).
Our plugs are designed for a slip fit and won't fall out easily without o-ring. The outside diameter of the cap portion is nearly identical to most reduced barrier air conditioning hoses to ensure when routing hoses through openings if the cap end of the plug fits, the hose will too without issue.
Our barrier hose plugs can be used as is, or install the appropriate size o-ring in the groove of the plug for a more moisture proof seal and snugger fit.
These plugs are inexpensive enough to keep a couple of sets on hand for installation of hoses, or just one set for service (leaving components disconnected including hoses we recommend the use of the o-ring) to keep your mind at ease.
Color coded for ease of identification (White = -06 hose, Light Blue = -08 hose, Red = -10 hose, Gray = -12 hose) makes quick work of selection of appropriate plug for the hose, or identification of hoses as they are routed through dark areas (under hood, body panels, under chassis, etc).