The Ecopro LegacyPro Ascorbic Acid Powder Black/ White Film Developer (Makes 5 L) is a 2-part powder black and white film developer. LegacyPro gives you high image quality, fine grain and sharpness equivalent to Kodak Xtol black and white film developer. The mix dissolves in room temperature water and is meant to be used at full strength or diluted in a ratio of 1:1. Part A must be completely dissolved before adding Part B. The quantity provided will make 5.0 liters (1.3 gallons) of developer. This product is hydroquinone free.