This is a replacement for the air filter material only. The air filter on the Compu-Dobby or E-Lift consists of a plastic holder that contains a piece of filter material. This product will replace the filter material inside of the plastic holder.
This filter is 2.36" square and will replace the filter for the Compu-Dobby IV, Compu-Dobby 4.5, and the Jacq3G.