Fuel capacity was 595 L (157 US gal) for the H-0 model, with the option of a 300 L (80 US gal) drop tank on the centerline.[citation needed] The H-1 model carried an additional 454 L (120 US gal) of fuel in six unprotected bag tanks in the wings; typically, one of these tanks was used to hold the MW 50 methanol-water mixture and another for GM-1 nitrous oxide. The H-1 could also carry a 300 L (80 US gal) underbelly drop tank.[citation needed]