The Lower unit consists of 3 tubes with diameters of 36mm, 39.75mm and 43.5mm. Closed length is 107cm. Maximum extended height is 283cm. The Pole Series 2 Lower unit can also be used with Pole Series 1 to extend the maximum height to 550cm. Maximum recommended loading is 2kg for all poles at full vertical extension. The lower unit is not designed to be used alone.