Studs x8 is a Red Brick in LEGO City Undercover which multiplies the value of collected studs by eight. This stacks with other stud multiplier bricks for a maximum multiplier of 3840.
During Special Assignment - Disruptive Behavior, when Chase McCain reaches the second area the red brick can be seen in an area protected by laser beams. To switch off the laser beams and get the red brick, use Rex Fury to open the nearby orange-handled box. Opening the box reveals an Astro Crate. Activate the astro crate to create a switch. Flip the switch to disable the laser beams and get the red brick.