Future Motion, the maker of Onewheel electric skateboards, is recalling all models of its e-skateboards after four known deaths were linked to the products, according to a federal safety watchdog.

The company issued the voluntary recall of 300,000 boards in conjunction with the U.S. Consumer Product Safety Commission after initially resisting CPSC's push for a recall several months ago.

"Future Motion has received dozens of reports of incidents involving the electric skateboards, including four reported deaths between 2019 and 2021 and injuries such as traumatic brain injury, concussion, paralysis, upper-body fractures, lower-body fractures and ligament damage," CPSC said in the recall notice released on Friday.

The reported deaths resulted from head trauma, the safety commission said. In at least three of the deaths, the rider hadn't been wearing a helmet during the incident.

Onewheel skateboards have a single, fat-tire wheel that self-balances as electric power propels the rider forward.

"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," Future Motion said in its recall notice.

Future Motion says it's adding a new safety feature to remedy the issue.

It's rolling out a "haptic buzz" alert function that "riders can hear and feel" when they may be in danger of crashing. The safety update will be made available for the Onewheel GT model in one week, and the Pint X, Pint and XR within six weeks, the company said. The original Onewheel and the Onewheel+ aren't eligible for the update.

In November 2022, CPSC warned consumers to immediately stop using all Onewheel models due to the risk of death and serious injury, while noting the four reported deaths.

The CPSC said Future Motion refused to agree to a recall at the time but that it would continue pursuing a recall.

In response to last year's warnings, the e-skateboard maker rejected the safety commission's "unjustified and alarmist claims," and said it saw no reason for riders to stop using their boards.