Hundreds of thousands of Onewheel electric skateboards are being recalled after four people have died using them since 2019, the Consumer Product Safety Commission announced Friday.

The self-balancing skateboards, manufactured by the brand Future Motion, have also led to injuries, including "traumatic brain injury, concussion, paralysis, upper-body fractures, lower-body fractures and ligament damage," the CPSC said.

"The skateboards can stop balancing the rider if the boards’ limits are exceeded, posing a crash hazard that can result in serious injury or death," it said in its announcement.

The four deaths resulted from head trauma, according to the CPSC, which added that in at least three of the incidents the riders weren't wearing helmets.

People who own the skateboards should immediately stop using them, the CPSC said. Owners of certain models — the Onewheel GT, Onewheel Pint X, Onewheel Pint or Onewheel+ XR electric skateboards — should download or update the Onewheel app and get the Haptic Buzz alert functionality for their boards, a vibration warning system that lets riders know when they could be susceptible to crashed, allowing them to lean back and slow down, Onewheel said. The updates will be available in the coming weeks for eligible boards, it said.

The original Onewheel model and the Onewheel+ aren't eligible for the Haptic Buzz update and shouldn't be used any further, according to Onewheel, which added that owners of the boards can get $100 credits toward purchases of new ones.

The 300,000 skateboards included in the recall were sold online and at independent stores from January 2014 through last month 2023 for $1,050 to $2,200.

Future Motion is directly contacting known buyers, the CPSC said.