I've installed a bunch of these from about 10 different sources and the Whisperlatch version is the best quality... but still pretty sad for what you pay for them. I've had to replace a few of the Whiperlatch on my own boat
after the plastic that holds the return spring broke, but it is still a lower percentage of failure than the cheaper models straight from China
, and the chromed brass fo the knob and grommet is beautiful. They are typically around $15 in the US.
WhisperLatchâ„¢ Cam Latch Cabinet Hardware - ITC RV
I've never seen one that had a metal body, they are all plastic in the mechanism (and where they fail). It's just the knob and surround that is metal on the better quality version.
You really don't want anything that is zinc based since they corrode pretty quick just from salt
The first version you linked to on Amazon is all plastic. Read the reviews