this pack of 50 m3 x 1/4in computer screws are great to have on handy for building, repairing, and maintaining computer systems, for mounting any motherboard to your pc chassis or attaching any floppy/cd-rom/dvd-rom drives. applications: installing the many different types of m3 threaded computer hardware such as optical drives (cd/dvd/bd) system builders/technicians who regularly build computer systems or install new hardware hardware thread type: m3 (outer) m3 (inner)