I found this on Amazon recently and added it to my latest order.

Houdini and Weezie love it. We already have a donut track which just goes around... and they still play with that. Oreo couldn't be bothered!
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But this track is so nifty... I am going to get a second and connect them. Not really expensive...available on Amazon for about $13.00 for the basic one shown in this YouTube.
Easy to assemble, and quite clever IMO.


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Easy to put together, nice looking and both our cats are having fun with it. I have it in a ? pattern, so one kitty pushes the ball on one end, and the other returns it. The ends are designed to return the ball anyway, which gives it a "real live" quality of movement.

This video shows the track without the covers, used outside.
This is two sets hooked together.
Still fun:

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