It will need a new cord from the receiver to the phone, because the plastic piece broke off due to age.. Minor wear on the base metal plate and some surface dust, otherwise gently used.
Western Electric Model 500DM rotary desk phone in red. Bell System property stamp on the base. Adjustable ringer volume control. Manufactured in 1979.
The 500 series ran from the late 1950s through the early 1980s and is one of the most collected vintage desk phones out there. The 500DM variant with the ringer control is harder to find than the standard 500.
Red is a premium color for this model. Clean red 500DMs with the DM suffix go for more than the basic ivory or black versions, and this one is priced to reflect the sticker residue on the base rather than ignoring it.