39mm. Fits '87-later XL (except XL883N, XL1200N, XL1200X and '11-later XL1200C), '91-'05 Dyna (except FXDWG) and FXR models (except FXRT) with 39mm front forks. (Does not fit with Chrome Fork Sliders.) These chrome Fork Braces are machined from billet aluminum, then polished and chrome-plated to complement the curve of the front fender. The machined Screamin' Eagle logo finishes the look with crisp detail. Easy to install, these braces offer increased torsional rigidity.