As a finish carpenter and cabinetmaker, I hang doors and install other millwork items to close tolerances for a living. This German-made telescopic rod takes the guesswork out of taking precise inside opening measurements. It is beautifully made, a true precision instrument. That said, two design changes would make it much more ideal for my use, both of which are available in different models by Nedo and also by other German manufacturers who do not market to N. America. The first improvement would be a unit whose individual sections can be clamped to one another to hold a fixed overall length. This can be very handy as the locked tool becomes a gauge for quickly establishing either maximum or minimum measurements across an imperfect opening. This Nedo tool has sufficient friction between individual telescopic members to reliably hold the measurement while you bring the viewing window end of the tool away from the work surface and into reading position, but that friction is not enough to allow its use as a gauge: if you push the extended tool against a fixed surface, the individual sections will slide back into the one another. Nedo makes other models that include this locking function, but they are much longer when contracted than I prefer to carry in my toolkit; correspondingly, they extend to far greater lengths than my work requires. The fact that the viewing port is located at the end of the tool, rather than in the middle, is a second feature that is less than ideal for my purposes. I have used other similar devices (custom builds of my own design) that allowed the measurement to be read from the interior end of the largest section, or even in the middle of the extended length. The advantage: e.g., you can read a measurement at ceiling height from a ladder in the middle of the span, such as for crown molding. I've seen (German) models with this center-read design, but they are not offered with Imperial scale, therefore not ideal for my work in U.S.