Linear low-density polyethylene CENTENNIAL Storage Tanks are ideal for acids, bases, and other corrosive compounds. One-piece seamless construction for maximum impact strength. Chemical- and stress-resistant. UV-protected against sun deterioration. Easy-to-read gallon markings. Materials have been approved to meet FDA standards. Bulkhead adapter fittings available, call for more info. Made in USA.NOTE: NPT Outlet for models 54100, 54101, 54102, and 54103 is 1-1/2". All others is 2".Fill Fitting for models 54100, 54101, 54102, 54103, and 54104 is 6". All others is 12".