Are you still looking for info? These kinds of all-in-one, "does everything" seats are generally a bit of a false economy, although this model is very cheap. I believe this one is made by BabyAuto for Online4Baby, it looks like a clone of the BabyAuto Volta. It might be one of the better options as these budget seats go but there are still some points to be aware of.
Info for the Puggle Lockton specifically:
It looks a bit complicated to fit. For rear facing, you have the option of top tether + isofix. For this you'll need to check you have a top tether point in your car, you can look in the boot for this. Older cars may not have one. For seatbelt fitting, you have to remove the insert, and then replace it in order for the seat to be used. The forward facing fitting looks straightforward, although I don't understand why they do not use the top tether, which is a more secure method.
The seat advertises a spin function, but you can't actually spin the seat when it's installed properly. There are other seats on the market which can spin when installed, although they are not as cheap as this one.
The rear facing mode in this seat can only be used in the reclined position, which can be frustrating for older babies and toddlers and means the seat takes up a lot of space in the car.
Rear facing is considered the safest option until at least 4 years old, but this seat can only be used rear facing up to 13kg, which is approx 18-24 months. Many multi stage seats can rear face up to 18kg, approx 3-4 years, and purely rear facing seats can rear face up to 25kg, approx 6-7 years.
Info for multi-stage seats or all-in-one seats in general:
It is likely to be a bit of a pain to convert it between stages. If you have grandchildren in both the harnessed stage and the booster seat stage, it's normally better to buy a separate harnessed seat and then a booster seat as storing two is a lot less annoying than converting it back and forth, and less chance of errors routing the harness, which could be really dangerous.
If the children are tall/heavy for their age, it might not accommodate them in the 5 point harness for long enough. You can buy seats which can harness for longer.
Often the fit for children at the edge of one of the stages (so approx up to 6 months, then 3-4 years, then 8+ years) can be poor, for example harness belts are too short to easily do up or the seat is too large; inserts do not fit the child well.
They often tend to perform worse in crash testing compared with seats which cover one stage rather than converting.
You can view the product info video here which demonstrates fitting method and also how to convert it between harnessed and non-harnessed mode.