The invention herein allows for manually positioning telescoping members relative to each other in a variety of positions within a given range of motion such as for movable chair backs or arms. A strut is engaged with and telescopically slides in a mounting member while deformable guide members provide for frictional engagement of the strut within the mounting member. A détente limits the range of motion of the strut relative to the mounting member. The détente comprises a stud or tab which engages a slot in the mounting member.