N Glossary Terms - N Narrow Stile Door Usually a door having a stile less than 2-3/4” wide, commonly seen on aluminum or glass front applications. Noise Unwanted signals picked up in an electric circuit. Non-Ferrous Pertaining to parts which do not contain iron. Ideal for use in corrosive environments. Non-Sized Closer A closer whose spring tube design allows full adjustment of the spring power size from 1 through 6.