I bought a plastic box with a top at Home Depot. Inexpensive and ugly, but it will protect. I have not used it yet.
Because the DP has protruding knobs, I would either use a box (like I bought) where the knobs touch nothing, or a case where the unit is surrounded by soft foam or padding.
A small suitcase and a non-shedding blanket would likely work well. Probably under $10 for both at a thrift store.