When making custom brake lines using a braided stainless, cut-to-length compression brake line kit, this tool is a must. It is sized perfectly for any brand -3AN braided hose and opens up the hose's braiding. This allows the AN fitting's 'olive' (metal compression fitting) to slide over the PTFE. With this tool, the process is super fast and easy. Without this specialty tool, very difficult, not as good as an end result, and likely some painful fingertips, having been pricked repeatedly by stainless steel wires! This black-anodized, aluminum tool with steel insert will last a lifetime.