Cap having a low cost construction and a self retaining feature

A cap for closing a duct tube, the cap comprising:

• a side wall, the side wall having a cylindrical configuration that extends around a hollow interior volume of the cap, the cylindrical configuration of the side wall having a center axis that defines mutually perpendicular axial and radial directions relative to the cap, the side wall having an axial length that extends between an inward, closed end of the side wall and an outward, open end of the side wall;
• an end wall connected to the inward, closed end of the side wall, the end wall having a circular configuration, the end wall extending across the cylindrical configuration of the side wall and across the hollow interior volume of the cap;
• an end surface on the outward, open end of the side wall, the end surface having an annular configuration that extends around the side wall and around the hollow interior volume of the cap;
• a pull tab on the outward, open end of the side wall, the pull tab projecting from the end surface;
• and
• a finger grip projecting outwardly from the pull tab.

A method of capping off an open end of a duct tube, the method comprising:

• positioning a hollow interior volume inside a side wall of a cap adjacent an open end of the duct tube;
• and,
• pulling pull tabs projecting from the side wall of the cap toward and over the open end of the duct tube;
• providing a respective finger grip to project outwardly from each of the pull tabs;
• and
• pulling the side wall of the cap onto the open end of the duct tube.