Tunze Osmolator Calcium Dispenser, Good Unit?

[sditch]

I have a Tunze Osmolator 3155 and was looking at adding this Kalk dispenser on my setup. I have a 120gal and thinking it would do the trick and looks easy to maintan.

Anyone has anyfeedback on this product or know of a good unit to use with my Osmolator 3155 to top off with kalk?

Thanks,
Sean