This is a long Torx bit you can use to open up a vintage compact Macintosh computer. It has a standard 1/4 inch fitting, so it will work in most interchangeable handles. When inserted into the deep screw holes, a few inches stick out so you can just use the bit if you're strong, or twist it with some pliers to loosen the screws (or use a standard handle).
Have fun tinkering with your old Mac!