Lids for gridfinity boxes, with handles! Designed for a personal project but I liked the result enough that I figured I might as well share.
Fully parametric, so if you don't like the sizes of the handles or want bigger lids or whatever, download the OpenSCAD file (and kennetek's "Gridfinity Rebuilt in OpenSCAD", which my OpenSCAD file relies on) and tweak to your heart's content. Otherwise, STLs for lids with a default handle size that I liked and found comfortable to use are provided for grid dimensions from 1x1 through 5x5.
For reference, the 5x4 lid shown in the photos used about 100 g of filament and printed in about 3 hours on my Bambu P1S.
Enjoy :-)