The picture shows a view of this Old Sealtest Milk Advertising Glass Shaker Bottle. The bottle is not dated but it is old. It has a white coating on the inside that makes it look like it is filled with milk. There is a tin cap with holes on top and a red and white decal on the side. It is marked as follows:
SEALTEST SEALTEST SYSTEM OF LABORATORY PROTECTION NATIONAL DAIRY PRODUCTS CORPORATION
It is unknown if this is one of a salt and pepper shaker set. The bottle measures 3-3/16'' tall. It is in excellent condition as pictured. There is some wear on the label and some corosion on the cap.