The Level for Rods and Poles With 40 Minute Vial is a leveler for rods and prism poles, fastening it to the pole or rod will assist you in determining that it is erected perfectly upright. This leveler comes with an added leveler on the side so that you can view it directly at eyelevel thereby providing an element of safety that construction and surveying professionals need in traffic-congested or other potentially hazardous job sites. It also makes it simpler to level and accepts all shapes of rods and poles, sizes 1 to 1.25-inch diameter.
A 40 min. vial is a less sensitive leveler than the 20 min. or 8 min. it would be best for projects that involve holding the pole by hand thereby providing accuracy for extended time, whereas the other vials though they are more accurate won’t be able to provide the best in areas with lots of vibrations such as near roads or at construction sites, therefore in those areas it would be best to use a 40 min. vial.