My trusty Robart paint shaker died after many, many years of faithful service. Sometimes near the end it would lock up and I'd have to take the bottom off and nudge it along and then it would work fine for a while. When it did finally die I bought one of the silver fingernail polish shakers as pictured in the first post from Amazon. I haven't had it a long time and while it's a little bit noisier than the Robart, it seems to do a fine job.....jury's still out.