From the October 1948 Popular Photography Giant Directory Issue...
edited to add the text because it's hard to read:
Kodak Tri-Chem Pack saves time, saves trouble, saves chemicals. It's especially convenient if you develop and print in your kitchen or bathroom. You make what you use: use what you make; no surplus to bottle and store. And you can depend on uniform results - with fresh new chemicals every time.
Each Kodak Tri-Chem Pack makes 8 ounces of developer, 8 ounces of stop bath, 8 ounces of Fixer...enough to process two rolls of 620 film, or fifty 2 1/4 x 3 1/2 prints, or their equivalents.
Mixing's quick and easy. Tear off corners of packets and pour contents into prescribed amounts of water. (Detailed instructions in each kit.)
Each Kodak Tri-Chem Pack contains:
Kodak Universal M-Q Developer
Kodak Universal Stop Bath with Indicator
Kodak Universal Fixer - all in foil packets
Price - 20 cents