We have personally used this product for our youngest when travelling and found it great. Weighing less than 5kg it is easy to bring it on board and use on an aircraft and when you reach your destination you will have a safe rear facing car seat that can be installed quickly and easily with a car 3 point seat belt. No more stress about what car seats the car rental company will provide (this is not recommended due to the treatment of rental car seats) and whether they are safe and if they will fit your child and the rental car properly and you don't need to bring your everyday car seats in the hold (from personal experience we have had to gets ours replaced as they got damaged from being thrown). (Note: We can facilitate separate payment for people purchasing for group use.) HyFiveOne TT – City is perfect for urban families, driving a lot in the city. It is the first foldable & ultralight child seat for everyday use, which is quickly assembled and installed in any car. The Nachfolger HY5 is a real innovation in the child car seat market. This rear facing child car seat is ultra light and safe at the same time. In contrast to conventional child seats, the HY5 weighs only 5kg! It can be folded small, easily changed between two cars, taken on trips and used in taxis, car rentals, car sharing and airplane travel. The inflatable child seat is a real trendsetter for modern families who travel a lot! Now you can use the Nachfolger HY5 on board an aircraft!! TÜV Rheinland and Luftfahrtbundesamt have approved the use on board with Travelkit (includes belt shortener). From 0 - 18kg rear facing only. Newborn inlay available for use up to 6 months. Evolution Air The Side-Air-Suspension system fills ups automatically with the included Highend accu pump in just a few minutes. The intelligent two-colour LED warning system indicates ready-to-use and sends signals when the pressure drops below the requires system pressure. As the HY5 has a standardised valve you can also fill up at petrol stations. With the quick release button, the seat can be folded down again quickly through the patented folding mechanism. It comes with a carry bag which also transforms into a seat protector with tablet holder. Certification The HY5 is certified under UNECE R44 and meets ADAC's high standards as well as those of the "Siftung Warrentest" and has passed countless tests in both Europe and Asia. In addition, the child car seats were tested for temperature changes, pressure loss and behavior with foreign bodies. The results were outstanding: the HY5 proved in the tests that it is extremely stable, but at the same time yielding and energy-absorbing. The seat acts as a protective airbag, providing perfect protection for your child. Rearward facing for children from 0 to 5 years (up to 18kg) with body size from 50- 105 cm Newborn inlay available for use up to 6 months. Reduced travel weight of only 4.6kg Compact, space-saving shape (5cm shorter than HY5) Installed with car 3 point belt and with Top Tether strap in the back seats (optional in the front passenger seat).  The HY5 World can be used without top tether, in both back and front seats. Patented folding mechanism (airplane cabin size) Including a bag that is also the cover and seat protector Including a mobile pump and USB charging cable (worldwide standard!) NEW – Easier to use due to shorter inflation time NEW – Higher safety due to an improved Air Control System  Installation with 3 point seat belt and top tether point. The HY5 can also be installed in the front passenger seat and the airbag must be switched off (The top tether point is not required when installing in the front passenger seat as the front dash takes over this function. The HY5 must be positioned as close as possible to the dashboard so that it rests on the dashboard) Easy to understand installation in the vehicle. Uncomplicated buckling of the child by means of three-way belt system. Individually height-adjustable headrest with integrated neck roll. The height adjustment is infinitely variable and thus allows your child the best possible protection and comfort. Headrest must be positioned with two fingers width between the child's shoulder and the headrest. Pull the headrest upwards at the top and guide it to the desired position. Two belt positions for small and large children. Covers are quick to remove and washable. ACS with standard batteries: 3 x AAA (available worldwide) External dimensions when inflated: width 41 x height 58 x depth 66.5cm Inside dimensions when inflated: width 32 x backrest height 56 x leg rest length 25cm Dimensions (in the bag): length 43 x width 33 x height 25 cm Dimensions (outer box): length 45 x width 35 x height 27 cm Weight including packaging: 7.0 kg A fully charged pump can fill the seat 2 times at least