I bought this faucet a few days ago and now love it. However, immediately upon installing, it leaked at the swivel joint for the sprayer head - not where the sprayer threads into the hose. The exploded view in the installation guide shows a gasket at that interface but nothing else.
Assuming I had a defective unit, I planned on returning it. But it kept bugging me so I decided to fish out the flat gasket. Upon doing so, the next thing I found was an O-ring. Underneath that was the flat side of a hard plastic U-shaped washer, and finally it was the start of the flared water fitting. This is a long way of saying that it arrived from the factory assembled in the wrong order. The O-Ring needs to go in first and rest inside the channel of the plastic piece (installed second) so that it seals off the water fitting. The gasket (third) goes in next, and lastly the sprayer head. It was immediately fixed.
Wrote this in case others have a similar problem. I fear that if I wasn't a mech eng, I wouldn't have found the issue. @Kraus you might need a corrective action in your assembly line lol.
4 stars for the headache, would have been 5 if working out of the box