TomTom ONE-S Edition Auto Navigation System Clamshell. TomTom ONE S with Text to Speech combines ease of use, portability, touchscreen technology and an elegant, unmistakable new design. Drivers can enjoy the benefits of a TomTom ONE S immediately, thanks to TomTom''s award winning navigation software pre-installed on the unit. This means there is no need to download complicated software, just start it up.