I agree with Kim. I myself am starting to use the 3/8x10 QR from Tom M. If you really need to find out if it's a 3/8x10 or 3/8x11, try contacting Carmeli with this picture, as he is the one that built it. If you pm jazznpool here on AZ, Martin may know as he is a dealer for Carmeli Cues.
HTHs
Dave