Abstract: A clamping device includes a flexible sleeve secured to one segment of a telescopic rod and having a collar for receiving the other segment, and two lugs displaceable between untightened and tightened positions, and an elastic lining member disposed on the collar such that, as a result of displacement of the lugs from the untightened position to the tightened position, the elastic lining member is strained to acquire a biasing force that biases the lugs back toward the untightened position, thereby facilitating telescopic movement of the telescopic rod during length-adjustment.