Digital salinity meter, which one is good ?

[M4rtin]

I tried regular refractometer, and it's horrible, at least it is for me to look through that tiny hole
What's good out there that's digital and would stay calibrated for more that 1 measure ?
I was ready to buy Pinpoint salinity monitor, but I'm finding few results of unhhappy users that state it need to be recalibrated before each use, not sure how much truth there is to it.
I have a budget of I guess $150, but what to buy ?

 

[Pivitol]

Milwaukee for the win!!

 

[foxt]

+1 for the Milwaukee. Easy to calibrate, use it all the time ..