Pick a Comdial system:

Executech II
Systems: N0308 - N0616 - N0820 - N1024 - 1432
Phones: 6600, 6614, 6620, 6622, 6706, 6714, 6700
Also: 3502, 3500, and many proprietary single line phones.

Digitech
Systems: G0408 - G0616 -
Phones: 7714, 7700

Impact
Systems are the same as Digitech with different software
Phones: 8012, 8024, 8312, 8324, 8112

Impression
Systems:
Phones: 2022, 2122

Unisyn
Systems:
Phones: 1122, 1022

DX-80
7260-00