Root's AIR IHC forks have built in IHC compression. What we love about IHC forks is that they save you money because they have compression built directly in to them. So just slide your bars over the forks and tighten 2 bolts on your clamp and you've got a super dialed scooter. Root IHC forks are available in their 5 standard color ways and, at an affordable price point, are some of the biggest bang for your buck IHC forks money can buy! Root Industries PRO SCOOTER FORKS are an aluminum pro scooter fork that work with the following types of compression: IHC. AIR IHC forks are IHC forks so the compression is built directly into the forks. A compression bolt on top of the forks compresses a shim onto the headset, eliminating the need to purchase external compression. Since you do not have to purchase compression AND forks when you buy IHC forks, IHC compression is an affordable and very popular compression system. Root Industries AIR IHC forks are durable forks and can be ridden on the street or at the park. The Root Industries pro scooter forks are compatible with the following wheel diameters: 100mm,110mm,115mm,120mm. Root Industries pro scooter forks are ONLY compatible with wheels with a 24mm core.