It can be used for mixing colors. Zelko has one up at JSR
we have one that was rebranded by Polyone - i believe the manufacturer is called "Andalok" and possibly from europe. it has a transformer to convert the 120v 60hz to 230 50hz.
the machine can shake 5g buckets if we needed it to, but mostly we use it for single gallons.
still needs some stirring after its shaken - sometimes the base and pigment isnt completely mixed.
if i have more than one bucket of ink i would use the shaker, otherwise i would stir by hand.