It can be used stock or diluted 1:1 for a sharper image with slightly more graininess. This is the go to developer for Kodak Double-X, Orwo UN54 and N75 as well as Lomography Potsdam and Berlin Kino 400 cinema films. Development time starting points are 7 minutes for stock and 10.5 minutes for 1:1. Comes in 1 litre and four litre pouches. Capacity is approximately 12 rolls per litre.