The Dual Screwdriver is a very handy, portable tool. It is a mix of a Phillips head and a flat head on opposite sides of the same tool. My tool fits in your hand nicely and has been tested to fit most screw sizes. With its fitting grip you will be able to tighten a screw with ease. My tool is very useful and would save someone from having to carry a Phillips screwdriver and a flat head screwdriver with them. Although it is only saving a small amount of room, every little bit counts in a confined place like the space station.