“Tumbler is a green and yellow concrete transport truck. He is the loudest machine on Bob's team... Tumbler “Flex is a yellow cherry picker. Flex Voice: Male Catchphrase: "Fantastic Flex!" Flex Pages in category "Machines" The following 2 pages are in this category, out of 2 total. F FlexT Tumbler Retrieved from "http://bert.wikia.com/wiki/Category:Machines"