My Fenton book and the catalog pages therein say these tumblers are 9 oz., 3949-BO. Fenton must have been gilding the lily a bit, when full to the brim they hold just a shade over 8 oz. No measurements are given in the book, but the tumblers are 4" tall and a little over 3" diameter.
The 48 oz. tankard jug was only produced between 1940 and 1944, so no specific line number.