This is a stand for the Arturia Drumbrute Impact. I think it's a 25-degree angle, but I'm not good at math. The rubber feet should line up with the two slots. If you have trouble getting the drumbrute to rest on the stand without falling to the side, consider affixing it to the back with painter's tape. I haven't had this issue yet but I could see it being a problem with aggressive drumming.
I printed with PLA at a .28mm layer height and 15% infill. Lay the model flat on its side before printing.
The author hasn't provided the model origin yet.