To perfectly prevent not only the fixation of an inner cylinder in the axial direction but also turning thereof with an external fastening type extension handle for connecting a cleaning attachment or the like freely to be removed.

The inner peripheral surface of an outer cylinder 1 is provided with axial directional recessed grooves 2 with an equal space, and a stopper 5 provided with lock projections 6 to be engaged with the recessed grooves to allow the axial directional slide of the inner cylinder 4 loosely fitted in the outer cylinder and to hinder turning thereof in the peripheral surface thereof with an equal space is fixed to the inner cylinder 4. Even if a large external force is applied to the attachment, since turning of the inner cylinder is hindered, the attachment can be tilted at a desirable angle for use.