A length-adjustable telescopic tube (1) has a longitudinal axis (L), an inner tube (2) and an outer tube (4). In one of the tubes (2, 4) a component (20) is arranged, which features first attachment structures (28a, 28b). The tube (2, 4) has second attachment structures. Furthermore, at least one plug-in element (50, 60, and 70) with third attachment structures (58, 68, and 78) is provided, which cooperate with the first (28a, 28b) and second attachment structures (48a, 48b) to form a form-locking connection with the component (20) in at least one direction along the longitudinal axis (L) or perpendicular to the longitudinal axis.