I've submitted an email question to Toto, but in the meantime thought I might ask here since Terry seems to install quite a few of these. I installed a Drake II in April, 2012 and the tank (ST454E) contained a red flapper with a weight on the chain. I just bought another one yesterday (Dec, 2012), same exact model tank (ST454E) and it contains a gray flapper with no weight on the chain. Was there a design change, or is this a manufacturing error?