Well, if you count Comdial's version of 1A2, he may have worked on Comdial and never encountered an Impact system.

Impact phone sets were only sold to Comdial dealer/partners. If you were not a prescribed vendor, you could get the Impression system. Same digital KSU, but the plastics on the phone sets looked more like the Comdial Unisyn analog key system sets.

Since the originator of this post only knows what type telephone sets are in place, they are going to have a tough time with any current or near-past Comdial equipment. Should make all you Comdial dealers happier, one less competitor.

it's all tip and ring