Radian® 3R Car Seat Manual January 30, 2024 23:11 Updated Please click here for your Radian® 3R Car Seat Manual. Related articles Radian® 3QX SafePlus™ (Radian® 3QX) Car Seat Manual Radian RXT (Manufactured as of May 2016) Is the top tether required on my Radian® 3R® car seat? Can I install the Radian® 3RXT® SafePlus™ (Radian® 3RXT® Safe+®) car seat with the UAS and vehicle seat belt? Can the Radian® 3R® car seat be installed if the vehicle headrest is removed? Comments 0 comments Article is closed for comments.