like others mention, round diamond stick.... there is a video on their site as well on sharpening them. so far, they are the second best head for edge retention I have shot, only one better has been iron will.... there is no single best head for everything, but I would put Kudu in the "good one" category. i'm still undecided what i'm shooting this coming year, but Kudu is still in the list of possibilities. it's my favorite stainless head I have shot, and that certainly has it's merits here. I can keep corrosion minimal on steel heads, but there is always some in this environment.