Lululemon Racer-Back Tank

This is a Lululemon Athletica black and charcoal grey tank top. It features a built-in bra, is non-constricting and roomy, and has an adjustable cinch waist. No defects to this tank that I can see, except this: I cannot locate a size or care tag inside of it. All measurements are approximate: Length down center of front: 21" Across underarm to underarm: 14" (This is likely going to fit someone with a size 34B bust.)