From Seven 20. I solemnly swear that I will drink more water. Messrs. Moony, Wormtail, Padfoot & Prongs proudly present The Marauder's Map-wrapped Harry Potter Water Bottle. You may be up to no good, but you can still hydrate. This 18-oz Harry Potter Water Bottle comes with a leak-proof screw top, limiting spills and condensation. Attached lid and convenient cup-holder-sized body make this your go-to source for on-the-go refreshment. Explore, remain alert, and stay hydrated.