Keep the box stored

" Please understand that if there is no machine box or internal buffer foam, it cannot be returned, repaired, or exchanged. Please do not throw away the machine box and buffer and store them separately. "


Is this natural English?

The sentence you wrote is mostly understandable but could be improved for clarity and natural flow. Here is a possible rephrase:

"Please note that without the original packaging box and internal foam buffer, the machine cannot be returned, repaired, or exchanged. We advise you to keep the box and foam buffer stored separately and not to dispose of them."