This is a Anvil/Paragon compatible dummy axle that is 135 OLD, not 137. Tig welders like the over size axles to deal with distortion when welding in bridges. For carbon builders and brazers with good heat control there needs to be a true length dummy. This is especially true when using disc brake fixtures (flat mount I’m looking at you) that need to be aligned parallel to the centerline of the frame. Made here in t ePNW by my friends over at https://lichenmfg.com/precision/.