def get_ext_coeffs(band):
    """
    Returns the extinction coefficient for a given band.

    Args:
        band: band name: "G", "R", "Z", "W1", or "W2" (string)

    Returns:
        ext: extinction coefficient (float)

    Note:
        https://www.legacysurvey.org/dr9/catalogs/#galactic-extinction-coefficients
    """
    exts = {"G": 3.214, "R": 2.165, "Z": 1.211, "W1": 0.184, "W2": 0.113}
    return exts[band]