This Alexander McQueen leather west comes from the early 2000s, most possibly as a non-runway piece from the SS 2003 collection, as it features similar design cues and nautical themes (Look 17 on the runway).
Judging from a similar piece found online, the vest is constructed in 100% python leather with suede tassel decorations throughout. The leather is laser cut to produce an intricate floral design.
The vest has slight damage on the right underarm. The composition label has been cut off and there are dark stains on the lining, most probably there due to wear with jeans.