Although the gender of tubing and plumbing fittings is usually obvious, this may not be true of electrical connectors because of their more complex and varying constructions. Instead, connector gender is conventionalized and thus can be somewhat obscure to the uninitiated. For example, the female D-subminiature connector body projects outward from the mounting plane of the chassis, and this protrusion could be erroneously construed as male. Instead, the "maleness" of the D-subminiature connectors is defined by specific presence of "male pins", rather than by the protrusion of the connector, which is also true for many other pin-based connectors like XLR. The male/female distinction is more obvious with ring crimp lug connectors which are placed around a screw post, but again with spade or split ring crimp lug connectors the end alone is not obviously female.