The 2851 was the only 6-button 1A2 wall phone made by Western Electric. Although it used the same model number as phones from other makers, its physical design was unique. Because of its shape, it was known as the "cuckoo clock phone."
Early versions used a plug-in handset cord like the 5-pin Trimline phone cord. Later versions had standard modular cords.
The phones were available with either attached 25-pair cables with Amphenol-type plugs, or with internal punchdown blocks for attaching cables without connectors.
A 10-button version was also made.