PURPOSE: To connect inner members in an external member by constituting a hooking device so that the hooking device supported by the inner member is engaged with the downward inner shoulder of the external member by an upward force when the inner member is placed in the external member.

CONSTITUTION: When a small diameter housing 18 is lowered in a large diameter housing 16, a finger 38 formed of a circular ring equipped in the housing 18 is bent inward. The finger 38 is bent inward along the tapered face 34 of the housing 18 as the finger 38 passes the inside face of the profile 22 of the housing 16. Further, when the seated shoulder 26 of the housing 18 securely lands on the seat face 20 of the housing 16, the tapered face 41 at the upper end of the finger 38 is engaged with the shoulder 24 of the housing 16.