evo.com | Full Tilt Ski Boot Parts > The Full Tilt FTE Flex 10 Boot Tongue is a replacement tongue for your Evolution (FTE) shell Full Tilt boots. A very stiff flex rating of 10 delivers the ultimate in power and responsiveness. Compatible with Full Tilt Evolution (FTE) Shell Boots Only B&E, Descendant, Plush Sold as a pair (2 tongues) X-Small 23.5 Flex Rating: 10 (1 soft - 10 stiff) A very stiff flex delivers the ultimate in power and response. Small 24.5 - 25.5 | Full Tilt Evolution Flex 10 Boot Tongue - X-Small in Black