Not glamorous, not high-tech, but still used by David Letterman, government, business, law enforcement, education, military.
Has five line buttons plus Hold button, mechanical ringer with volume control, intercom buzzer incandescent indicator lights. New Old Stock, with 90-day warranty. Modular handset cord. Line cord has 25-pair "Amphenol"-type connector.
Ringer is normally connected to yellow-slate wire pair for "common-audible" signalling on all phone lines. It can be re-connected to one individual line.
Free "ground" shipping in the USA. Limited supply -- order soon if you need this.