Manufacturers sometimes deliberately make it difficult to open their products. A common method is to use odd-shaped specialty screws. Without the right driver, the unit remains sealed. Wiha makes very high quality hand tools, and likes to offer them in great variety. They are a great source for premium versions of specialty screwdriver and screwdriver tips. This table gives a sense of what you can find. Of course they carry a great variety of premium tools in “ordinary” styles (Phillips, slotted, etc.) as well.