Anybody have any luck with the eBay PH meters?

[schwimmair]

Hi, was looking at a few Salinity Refractometers that include the cheap PH meters on eBay and was wondering if anybody has had any experience or luck with them.

 

Here is what I am looking at:

 

http://cgi.ebay.com/Salinity-Refractometer...=item35a785849d

 

http://cgi.ebay.com/New-Salinity-Refractom...=item4ced64a585

 

http://cgi.ebay.com/Salinity-Refractometer...=item4cede08dab

 

I have found a few things on Google that have said positive things about them, just wanted to see what everyone thought!

 

Thanks,

 

Schwimm