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, LED or incandescent indicator lights. Refurbished, with 90-day warranty. 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. A buzzer can be installed for intercom use, or to replace the ringer.
Other colors, and New Old Stock phones, are sometimes savailable -- ask us.