AP RO 15300 bracelet links and accessories

[Thunderbird88]

Dear all,

I'm about to go for an AP RO 15300, it's huge step up for me but I'll give it a shot.

First question, on a 15300 with 18 link pieces on the bracelet, how big of wrist will that fit? I have aroun 18cm wrist (about 7 inches). The person I bought it from will include one extra link piece as he was not entirely sure that 18 is enough for an 18cm wrist.
What do you think?

Next question,
What accessories are included in the box from new?
Outer box? Inner box? Manual? Certificate? Hangtag? What else? I know extremely little about AP. All I know is that they're beautiful

Thank you!