Tetenal is a great kit and it comes in 1 litre and 5 litre sizes. I've been using the 1 litre kit for 120 as well as for 35mm lately, having used the Rollei Digibase product and Unicolor kits previously. For the purposes of any of these kits, 1 roll of 120 is equivalent to 1 36 exposure roll of 35mm in terms of film area being developed. The exception is that processing 400 iso films will decrease the overall number of rolls developed in the Tetenal product.