I use my Vitamix 750 every morning to make smoothies.  The 64-ounce plastic container it came with looked grungy despite using the 750’s cleaning setting after each use.  When searching the Vitamix website for a replacement plastic container, I discovered the 48-ounce stainless steel container.  The stainless steel container cleans perfectly using the 750’s cleaning setting.  I am very happy with my purchase.