Adapter plugs to put 120 Size film into an old camera designed for 122 sized film spools (Eg. Kodak 3-A folding autographic brownie camera) Print with high infill (roughly 90%) so the tongue is strong. Requires a bit of filing down on some edges etc unless your printer is really accurate. Should be a snug fit but not too tight. I printed mine with supports turned on just for the keyway in the base. Depending on your printer you may not need support in this area but I used it anyway to be sure. Note it was a bit tighter on some Ilford brand film spools so could require just touch more sanding down on the edges and verticies of the tongue piece. Has been tested and confirmed working with Ilford and Kodak brand spools.