This part allows you to set the Infinite Rate Tune (IRT) pressure. IRT gives you the closest thing available to the feel of a perfectly chosen coil spring – without additional weight.  It allows you to control the mid-stoke rate independent from bottom-out. The 34mm IRT is compatible with the following fork models: • Mattoc Pro 2 • Mattoc Pro • Mattoc Expert • Dorado Pro • Dorado Expert Trail Tip: Set the IRT pressure before the main spring pressure. Always have the IRT pressure higher than the main spring pressure to ensure the proper balance of pressure chambers.