type-S fuse

type-S fuse

A fuse contained in a small glass or ceramic housing, which can be screwed into a screw-shell socket; it has a window for observing whether the fuse has been “blown”; available in three, noninterchangeable sizes (15, 20, and 30 amperes).
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.