The Stabila NL Telescopic Levelling Rod is made from anodised aluminium. It is extendable up to 2.4m with a scale in mm graduations. The adjustment slide ensures optimal display clarity and trouble-free height definition. Suitable for all STABILA laser receivers and receiving units. How To Use 1. Align the rods zero mark to the laser beam. 2. Move the receiver on the levelling rod to bring it back in line with the laser beams height at the new measurement point. 3. The height difference plus or minus can now be read from the NLs scale