Thai Tower

a.k.a. Clever Toys Tower
Purchased by J. A. Storer in Bangkok 2008, this puzzle also sold by Clever Toys.
(wood, 2.9"x4.1", five each red, blue, green, and yellow 9/16 inch diameter balls)

There are four columns, which when solved, each have 5 balls of the same color. The ends cannot rotate; one has a single receptacle that can hold one ball and the other has one receptacle for each column. Harder than the Varikon Towers, but easier than the Babylon Towers.

Solution: It is convenient to think of the bottom as the end with the single receptacle and the top as the one with four receptacles, and to work from the bottom up in three steps:
1. It is easy to place the bottom balls (it doesn't matter how you mix up the remainder of the puzzle).

2. The second and third rows can be fixed in a manner similar to the Varikon Towers (they are adjacent to the center by which the rings rotate).

3. The top two rows are adjacent to the top edge of the center ring and can also be solved in a manner similar to the Varikon Towers.