Convenience multiplied! Purchase an additional base for your Fit360? Rotating Convertible Car Seat (sold separately). With secure, one-time installation , the second base can be used in another vehicle allowing you to move the Fit360? seat from base-to-base. Installing the Fit360? base into your vehicle is as simple as open-route-close with innovative one-time LeverLock? seat belt installation. Open the LeverLock? door on the Fit360? base and route the seat belt using the easy-access belt guides. The car?s shoulder and lap belts follow their natural path through the guides for trouble-free belt routing. The built-in LeverLock? self-tensioning lock system offers superior stability with three points of contact for continuous use from rear-facing (4-40 lbs.) through forward-facing (25-65 lbs.) usage. By simply closing and latching the LeverLock? door, the vehicle belt is tightened in a way that eliminates any movement from front-to-back or side-to-side. This provides a secure installation with