Abstract: In order to minimize opportunities for dirt, grime, moisture and adverse atmospheric conditions to enter a fitting for coupling a flexible plastic tubes in a quick connect-type coupling, a collet used within the coupling has a constant diameter boss at one end and slots splitting the collet into spring fingers, which slots do not extend into the boss. The collet is received within a bore in an annular body, wherein the bore includes a cylindrical surface that is substantially completely engaged by an outer cylindrical surface of the boss, with the end of the boss projecting from the body a substantial distance beyond the bore.