The Headrush Backpack holds both the full-size Pedalboard in the large padded compartment AND it fits the MX5 perfectly in the top padded compartment. Therefore, if you bring a Pedalboard and a back-up MX5 to gigs this one backpack can hold everything Headrush related in one case with protective padded compartments for both units…plus all the necessary power and signal cables. it also fits in an airline overhead compartment which I think is essential to protect the units from damage when you travel on fly dates. My largest complaint about the Headrush Pedalboard was the poor build quality, especially the switches and motherboard…using this padded backpack to carry the unit helps protect the switches from damage. I’m surprised that the Backpack isn’t available because as far as I am concerned, it’s a necessity if you gig with the Pedalboard and want to keep the switches and motherboard from being damaged. Perhaps Headrush is getting ready to release a more robust Backpack.