It seems to be by that the wooden tea caddies were ranked lower than chaire, which features many 'meibutsu' (distinguished tea utensils), but the fact must be noted that they were originally used in the same way as chaire.
これは「名物」の多い茶入に対して木製茶器が低く置かれたからであると思われるが、本来は茶入と同様に用いられていたという事実は注意を要する。