new Diver (15 Dive) + Single tank + 40lt BP BCD

[inquis]

Neither 40 liters nor 40 lbs is appropriate for a single 15 liter tank, IMO. The job of the wing is to compensate for air breathed (4.5 kg) and wetsuit compression (which varies but is usually under 7 kg for a one-piece 7mm). Without knowing more about your particulars, I'd say a 30 lb wing or a 15 kg is a good target.

 

[dmaziuk]

That looks wide enough to be a doubles wing, in which case it still shouldn't have 40 litres capacity, but 40 pounds: easily.

 

[Rayk]

the seller wrote 40lt, i have attached a picture to help understand the size. i'm located in europe so maybe the size are differete, to be honest i have not clue

As a general principle, everything you may not want (horse shoe shape, double bladder and bungee retainers) combined into that wing. If I were you I would pass.