Complete set of 12 cardboard milk cap discs, each 1-5/16" dia. From a numbered series issued in 1941 by Roberts Milk. Each cap features same full body image of Superman in classic pose w/hands-on-hips. Text at edge of each reads "Save All Twelve Stamps - Become Member Of Roberts Superman Defense Club." This text is the same on each milk cap, but each features different numbered pledge. Reverse of each is blank. Lids were redeemable w/milk company to receive brass Superman American pin. Varying degrees of typical soiling but no creasing. Fine overall. We have offered individual pieces from this set in the past but this is only the second complete set we've offered in our 48 years. Only a few complete sets are known. See following items #2087-2088. Franco Toscanini Collection.