Thecus used their double box packaging with the N8900, the same we've seen with all of their rackmount NAS servers.
The outer box is fairly thin and serves to preserve the inner box that has the product branding on it.
On the inside of the box we found a layered approach. The drive sleds are not mounting inside the NAS when it ships - they are housed in a foam layer.
Going one layer deeper, we found the accessory packages and drive rail box. This is where the dense foam starts to emerge and the real protection comes into play.
The NAS is on a raised section. On the bottom of the NAS layer is dense foam and the NAS has a good three inches of foam between it and the outside corners. The corners are usually where UPS and FedEx drop their packages when they get thrown on and off the planes.