I bought these for use by an after school club: primarily when staff are walking children between the setting and our local primary school. Because the vests are to be used by different people, with different clothes sizes, a family pack containing both children's and adult vests seemed ideal. I bought two packs.
The vests themselves are of decent quality, but - inevitably - the pack that purports to fit everyone doesn't fit anyone well. The children's sizes go up to age 11, and are consequently VERY big for young children, but can be tight at the higher end (though in these cases adult bibs can be brought in to play). Similarly, larger/smaller/unusually proportioned adults won't be best served by these.
If you don't have an ongoing need for person-specific sizing in safety wear, but rather want a pack of high visibility vests for short-term use, 'in case', or for use by different people, then these are ideal and a good budget buy. But if e.g. you regularly cycle with your little ones, it would be much better to invest in individual vests in the proper sizes.
A possible France drive-stay courtesy of family friends isn't yet established, but it's really useful to know that high-vis vests are now a French govt. requirement, thank you!