Sliders for closing the zipper of an evacuable storage bag. The slider is generally U-shaped and comprises a pair of mutually opposing sidewalls, a bridge connecting the sidewalls, and a generally U-shaped stiffening rib projecting outward from the sidewalls and bridge. In accordance with various aspects of the invention: (1) portions of the sidewalls on both sides of the stiffening rib have undulating external surfaces that facilitate manufacture by injection molding; (2) both sides of the stiffening rib are provided with respective curved depressions that are generally symmetrical relative to a central plane of the slide and that facilitate grasping by the storage bag user; and (3) retaining hooks at the distal ends of the sidewalls have angled surfaces that form an included angle of 30 to 45 degrees at an entry point into the gap between the sidewalls to facilitate automated slider insertion onto a zipper.