These Whites fork seal insert tools are made using the traditional split design. These are constructed from hardened and tempered carbon steel and finished with a zinc plating for corrosion resistance making a strong and durable fork driver. A knurled outer grip limits the risk of slipping when hands are oily. Evenly drives your fork seals and prevents damage to your forks compared to other methods. Works on both conventional and USD forks. This is for 48mm forks.