UPDATE: I originally gave a one-star review. The product still stinks, but the customer service was awesome. They contacted me immediately after seeing my review and offered a refund, which I received the same day. REVIEW: I had a pinhole leak in an air line operating at 140 psi. I cut out the section with the hole and joined the two ends with one of these connectors. It leaked immediately. I bought a two pack, so I took the first one off and tried the other one. Leaked immediately. If I physically pulled the air line from both ends, the leak from the connector substantially slowed, but as soon as I released the line, it started leaking again. Nothing but junk. I cannot understand how anyone got these to work, unless there are a bunch of fake reviews.These things are a little pricey but they work good and do not leak.These are much nicer and more durable than the plastic ones you see all the time. I am a Ford Diesel technician and in order to lift cab on a 6.4L to do a motor i had to cut the customers air line due to routing. I installed this right after lowering the cab. It went on easy and no air leak.Bought these to replace the leaking plastic ones. They work so much better and no more leaks.Much more better than plastic one hopeful it can keep working for long timesI am so far very happy with these unions, strong and seemed to be made very well. Super ValueEs perfectoThese are really nice quality quick connect fittings. They are easy to use on air shock lines. They always work well for me.