I wouldn't ship via DHL personally. They seem to damage a lot more than Fed Ex or UPS.
When I shipped the last set of heads, I took a piece of scrap 3/8" plywood and cut it larger than the footprint of the heads. I drilled 4 holes in it and than used large zip ties to fasten the head to it. Than just boxed it up normally. Kept it from doing any shifting in the box and potentially tearing out. The buyer sent a note saying he appreciated the extra efford in shipping prep. They came through with 0 damage.
DHL use to be Airborne. They were one rough outfit, and still are IMO.
That was one of the tips I was going to pass along for shipping heavy items cat. It also helps if the carton is breached to keep the critical surface from damage. One other tip, never use peanut foam like the shipper of the pair of heads I got. Also box them separately.
