NEW YORK (CBSNewYork) — The latest toy craze fits in the palm of your hand.

It’s gaining popularity among children and adults alike, and it isn’t just used for fun.

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There’s the Fidget Spinner, which you simply spin, and the Fidget Cube, which has something different to press on each side, CBS2’s Alice Gainer reports.

West Side Kids toy store was sold out of the cube.

“They’re very, very popular,” assistant manager Michael Niles said. “It really surprised me a lot. I’ve personally tried it and I honestly don’t see the fascination with it.”

Christina Burek, a mother of four, gets it.

“We have a lot of Fidgets. We want that one. We haven’t bought it yet,” she said.

The Fidget Cube is the ninth-most funded project on Kickstarter, with creators raising nearly $6.5 million from backers. They say it’s designed to help you focus. Forbes even dubbed Fidget Spinners the must-have office toy for adults for 2017.

Mental health experts say fidget toys are nothing new, they’ve been using them for years, Gainer reports.

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“I think a Slinky is one of the earliest fidget toys,” psychologist Dr. Harris Stratyner said.

He said fidget toys are often used by doctors while treating patients with autism, anxiety, obsessive compulsive disorder and attention deficit hyperactivity disorder.

“When they fidget with a fidget toy, it takes their mind off — it soothes their mind. So it’s mind and body are one,” Stratyner said.

He said the toys can really help just about anyone focus.

“You can also generate ideas. It just centers you,” Stratyner said. “And when you’re fidgeting with something, your hands are feeding back to your brain a signal that you’re involved in a repetitive task. That repetitive task frees up your mind.”

“My kids have sensory issues actually, and some of them are ADD. But all of them like it,” Burek said. “It helps them think, helps them to homework.”

If these fidget toys don’t interest you, there’s always that good old Slinky.

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A Fidget toy will set you back about $20.