It doesn't look like a Brachy sling. Look at the mirror patch - completely wrong for a Brachy. Could be a Grammostola, but from overall appearance I'd put it into Thrixopelma/Euathlus/Homoeomma. Unfortunately there are quite a few slings looking like that.
Looks like it could be a Euathlus pulcherrimaklaasi. I could see that mistake being made with the small writing on the top of the vial that they are in. It is easy to mix them up going by the tiny writing on the lid. G.pulchra vs E.pulcher on the top would be easily mixed up.
I have Euathlus pulcherrimaklaasi and they look like this.