The file 'Tall 36-70mm Spool Adapter (Ender 3 V2) 3D Printer Model' is (stl) file type, size is 314.5KB.
This is a converter for spools with an internal diameter of 70mm, to fit over the 36mm cap on my Ender 3 V2. I think the same external size is on an Ender 3 regular, but your mileage may vary.