Wig Source: This is an Amazon wig purchased several years back.
Wig Size & Description: The wig is shoulder length and is a shiny black. It has been set in a half-up, half down style secured with Bobby pins and product. The bun isn't detachable.
Due to the amount of product used to achieve the original style, I'd advise against buying with any radically different hairstyles in mind -- unless you're committed to thoroughly washing out the wig before you start!
I have a larger head and this wig fits me nicely. It also has adjustable straps to help dial in the fit.
Current Condition: The wig was twice a few years ago (for Nana from BNHA/MHA) and she's been sitting in storage since. While the bun has hung in there pretty well, it's a little off-kilter and will need to be recentered on the back of the wig. It would only take a few minutes, but I leave that to you since it may need a little TLC after shipping anyhow!
Please let me know if you have any questions!