(CNN) Billionaire tech entrepreneur Elon Musk shared photos and videos of a metallic pod that may help rescue a group of boys trapped in a cave in Thailand.

Footage shared on Musk's Twitter account shows a group testing the device in a Los Angeles high school swimming pool.

Musk said in a tweet Sunday evening that the pod — or "kid-size submarine" — was en route to Thailand and would arrive in about 17 hours.

"Hopefully useful," he said in one tweet. "If not, perhaps it will be in a future situation."

His updates came after US and Thai officials confirmed Sunday that four boys had been rescued from a flooded cave network after spending 15 days trapped along with their soccer team and coach. They were escorted out by a group of Thai and international divers.

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