The base for the Primo Viaggio 4-35 is equipped with the “Right Tight System,” which easily and securely locks the base in place for added stability with either the UAS strap or the vehicle seat belt. The base has colour coded belt paths, which act as a guide for the vehicle seat belt routing. A modern design with a rounded-shape bottom allows for a better fit and is gentle on any vehicle upholstery. The Primo Viaggio 4-35 base includes a built-in anti-rebound bar for superior protection in the event of a collision.
High Speed 1 (HS1), formerly known as the Channel Tunnel Rail Link (CTRL), is a 108-kilometre (67 mi) high-speed railway line running from London through Kent to the British end of the Channel Tunnel.   It was built in two stages. The first section between the tunnel and Fawkham Junction in north Kent opened in September 2003, cutting London–Paris journey times by 21 minutes to 2 hours 35 minutes, and London–Brussels to 2 hours 20 minutes. On 14 November 2007, commercial services began over the whole of the new HS1 line. The redeveloped St Pancras International station became the new London terminus for all Eurostar services.  The completion of High Speed 1 has brought the British part of Eurostar's route up to the same standards as the French and Belgian high-speed lines. Non-stop journey times were reduced by a further 20 minutes to 2 hours 15 minutes for London–Paris and 1 hour 51 minutes for London–Brussels.