The 100-A was RCA's most popular speaker of the 1920's. introduced in 1927, it replaced the larger model 100. Both the model 100 & 100A reproduced excellent sound quality, far better than the best of the horn speakers. In fact the sound quality from these speakers was about "as good as it gets" in the 1920's.

This speaker will work nicely on any 1920s radio that requires a two wire external speaker (battery or electric).   

authentic replacement pattern of this cloth  available from: