A replacement item for Kalt stainless steel developing tanks, this Lid with Cap protects the film from light during development and also prevents chemistry from spilling during inversion agitation.
This lid is compatible the 35mm single roll, 120 single roll, 7", and 12" stainless steel tanks.
I recently pulled a loaded development tank out of my changing tent and found that the lid was split. I had noticed that it seemed a bit loose. Quickly put it back in and got a lid from another tank and di not ruin the entire roll. I was glad to find that you can easily obtain replacement lids. One recommendation I can suggest is that you never leave a lid fully installed on an empty tank for long periods of time. Apparently the stress of the tight fit caused mine to split radially across the top and edge.
It's not 100% leak-free, but I would say 99.6% It may let a few drops go through, but it works great and will maintain the value of your stainless steel tanks for a while.