This is the only common conic projection that represents the poles as a single point. The two standard parallels. All graticular intersections are 90 degrees. Small shapes are maintained. Arial scale is reduced between standard parallels and increased beyond them.
Local angles are accurate throughout because of conformity.
Correct scale along the standard parallels. The scale is reduced between the parallels and increased beyond the parallels. Best results are for regions predominantly east-west in extent and located in the middle, north, or south latitudes. Total range in latitude should not exceed 35 degrees. This projection was used for many new USGS maps after 1957.