The name "Shell" is also used in the names of various other font families, which are often the source of the search term. The most prominent of these is ShellSans Medium .
The generous x-height ensures that characters are easily distinguishable, reducing eye strain for the reader.
What is the you are designing? (e.g., website, logo, sign) Do you need a font for large headings or long paragraphs ? Which software are you using to create your design?