The latest trend hitting classrooms across the country is a colorful knick-knack that advocates say promotes focus, but some school administrators are reportedly banning the device, saying it has instead become more of a distraction.

The compact toy, a three-pronged piece of plastic that spins about a steel bearing, is meant to prevent fidgeting by keeping hands occupied and is supposed to improve concentration, calm anxiety and inspire learning.

“There seems to be a surprising benefit to these toys in class in regards to perhaps some sensory benefit that they offer kids,” said Dr. Louis Kraus, chief of adolescent and child psychology at Rush University Medical Center.

And the toys are increasingly popular, becoming among the hottest items to be sold on Amazon as instructional YouTube videos reach millions of views. At Learning Express Toy Store, the fidget spinners are so popular they have to be kept behind the counter.

“We get a lot of calls all day,” said owner Laurie Kherani. “’Do you have spinners in stock? Do you have spinners in stock?’ You know, ‘Thank goodness, we can’t find them anywhere.’ So yeah, it’s been great.”

But school administrators say the toy is also invading the classroom, with some claiming it is converting focus into distraction.

Schools in Downers Grove and Evanston have already banned the devices in the classroom, according to the Chicago Tribune.

And while there may be anecdotal evidence that the toys could be helpful to some students in the classroom, some experts say more research is necessary.

“Anything that might be a benefit for kids that could be as simple as this would be wonderful, but let’s understand it and make sure that it’s helpful and perhaps not a distraction,” Kraus said.