This running backpack closes with, among other things, a drawstring and lid. Black is just one of the colours you can pick from if you're going to buy this bag and it holds 18 litres.
From Bikeparts
Camelbak Arete Hydration Pack 18L With 1.5L Reservoir 2022: Black/Reflective 18L
This product is also available at 3 unverified merchants.
Too expensive? Get a notification as soon as the price drops.