Additional Information Hankook TH31 The 3PMS-certifie Hankook Smart Flex TH31 is an all weather tractor/trailer tire for variable road conditions. Highlights Main zigzag groove provides excellent traction and water drainage under various road conditions Asymmetric grooves helps eject stones Slanted groove design helps to prevent chunking Lateral semi grooves help improve initial traction performance Special chip-cut compound to enhance durability for severe conditions