This is a 0+ car-seat which can be used from birth to 12 months, or 0-13kg (approx 28lb). It can be installed either using your 3 point seatbelt, or used in conjunction with an easyfix/isofix base.
The shoulder straps have 2 height positions, to be altered as your baby grows. The seat has a removable head hugger, which itself has a removable sponge wedge. This means as your baby grows, you can remove the wedge giving them more room, and then as their head becomes stronger, you can remove the whole head hugger.
The handle has 3 positions, upright for carrying, semi-reclined for rocking the chair, and fully reclined as a stand to hold the chair steady on the ground.
The chair is compatible with many pram frames to be used as a travel system eg. Mothercare My3/4, Mura 3/4, Quinny, Bugaboo etc...
I have only ever used this seat with the easyfix/isofix base so with this, it's installation is very easy. I have never tried using the 3 point seatbelt installation. However I have a 3 door Mini Cooper and would say that those with smaller cars would perhaps struggle to fit this seat with ease using the seatbelt.
My son is now 6 months and 18.5lb (approx 8.3kg) and already seems to fill the seat quite substantially even with the head hugger removed so I am skeptical as to whether this will last him to the maximum age/weight stated by the manufacturer. And for many weeks now, it has been almost impossible for me to lift the seat with my son in it.
I would say this is a very good car seat, priced on par with the many others out there, but more universally compatible with many pram frames. If being used as a car seat and part of a travel system then this is highly recommended. If you do not require the car seat to slot into a pram frame then I'd say it would be better to purchase a combination seat (eg Maxi Cosi Opal) to face rearward from birth then turned to face outward from approx 9 months)