NFL teams are mounting GoPro cameras on quarterbacks during practices and games, with at least six franchises adopting the technology this season.

The cameras, long used in college football, were first experimented with by the Philadelphia Eagles in 2016, according to ESPN. Their use in the NFL has expanded beyond the quarterback position to include defensive players in some instances.

Teams report that the footage offers a quarterback-level view of each play and provides insight into on-field communication between the quarterback, center and other linemen. Coaches also use the video to evaluate protection calls and decision making at the line of scrimmage.

The league has not announced a policy governing the use of the cameras, and it remains unclear how the recorded material will be shared or whether it will influence future strategic adjustments.