While we don't yet have a dedicated case for the Arturia DrumBrute Impact, one of the cases in our INSERTLINE line may be a good fit!
The dimensions I have on hand for the Arturia DrumBrute Impact are: (12.6 x 11.4 3.54) inches. If that aligns with what you have, I would recommend looking at the UNISON Custom Edition: Compact: (15.1 x 13.7 x 4.7) inches.
