Extemely rare hard to find aluminum weight bolt for D series and possibly B and C cues I would guess. This is the lightest weight bolt they made. So if that McDermott is just to heavy this is the answer. No one has them that I have checked with. McDermott Co., they have not had any for years. They told me they are worth their weight in gold. They aren't cheap, and I only have a couple. First come, good luck.