Under Armour Sackpack. Under Armour SackpackCarry all your training essentials around in this Under Armour Sackpack. Constructed from a lightweight poly, this bag is crafted with a drawcord closure with sternum clip for an adjustable fit and is designed in a two-colour way design featuring Under Armour branding for a sporty look.> Bag> Drawcord closure> Sternum clip> Lightweight> Under Armour branding> 2 colour way options> 100% polyester> Spot clean with a damp cloth