def bodvrd(bodynm, item, maxn):
    """
    Fetch from the kernel pool the double precision values
    of an item associated with a body.

    http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/bodvrd_c.html

    :param bodynm: Body name.
    :type bodynm: str
    :param item:
                Item for which values are desired,
                ("RADII", "NUT_PREC_ANGLES", etc.)
    :type item: str
    :param maxn: Maximum number of values that may be returned.
    :type maxn: int
    :return: tuple of (dim, values)
    :rtype: tuple
    """
    bodynm = stypes.stringToCharP(bodynm)
    item = stypes.stringToCharP(item)
    dim = ctypes.c_int()
    values = stypes.emptyDoubleVector(maxn)
    maxn = ctypes.c_int(maxn)
    libspice.bodvrd_c(bodynm, item, maxn, ctypes.byref(dim), values)
    return dim.value, stypes.cVectorToPython(values)