Few tool companies are as well regarded as Wera. In the states, only tool nerds know the name, but tool nerds generally know what's up, about tools at least. Wera is the Makita of hand tools. The Voigtlander of screwdrivers. Wera isn't quite as Gucci as say, Knipex, but they're close. VW to the Audi. You get the drift.
Durable, precisely made, easy on the hands plus they look nice. We use Wera in the shop for hex screwdrivers, L hex keys and all our torque applications and hex drivers. The shape of the driving bit is unique. I don't know the math on it exactly, but it allows for more torque to be applied without slippage, which is what you want. Less damage to the fastener (bolt) and less wear on the tool.
Flat end hex drivers are great for quickly installing bottle cage and stem bolts, adjusting many contemporary derailleurs, rack mock ups. Final torque should be done with an L key or a torque wrench, but these Wera hex screw drivers get the bolt in quickly so you can save the torque wrench for the final snug session.
Made in Germany.