I put this here because it doesn't fit under Leather Tools and relates to sewing machine maintenance.. I got fed up trying to find the correct size screwdriver to fit the screws on firearms (they invariably use slotted screws) so lashed out and bought this set, 14 slotted, 2 Philips and 1 ridiculously small hex bit. Not cheap, but the quality is excellent (made in USA). I have numerous bit sets but none have the range of slotted bits that this does. It occurred to me that it should also be great for working on sewing machines as they tend to use slotted screws.
One other nice thing is the plastic case has a hinge, not one of those horrible flexible plastic hinges!