By combining one Tru-Pac C decorative conversion kit with one 60 lb bag of standard bagged concrete mix (3000 psi) found in home improvement stores everywhere, you get a 67.5 lb batch of mix for far less than your typical 50 lb bag mixes. By keeping a supply of Tru-Pac C kits on hand you can conveniently pick up the bagged concrete locally and save big money on shipping those 50 lb bags.