Don't rely on cheap bargain bin tools to work on your high-end bike. While buying cheaper tools might seem tempting, the old adage you get what you pay for may not hold any truer meaning than when it comes to tools. For adjusting limit screws on derailleurs or most any adjustment that requires a flat blade screwdriver, Park Tool's Flatblade Derailleur Screwdriver - DSD-4 needs to be in your collection. This precision component screwdriver is machined to precise tolerances ensuring a snug fit on slotted fasteners and prevents stripping heads. The ergonomic CNC machined handle is hard anodized from 6061 aluminum and is knurled to improve grip and its quality can be felt in its weight. The 5mm precision ground flat blade is durable and stays sharp for years to come.