Started recently creating a bunch of gridfinity items. Really did not enjoy how much filament was being used for some of the models, even small ones. So i started creating a good chunk of filament saving designs. 

Here is a quick 3/8" ratchet extension that can take pretty much any assortment of sizes. I left the ends open as well incase you have some REALLY long ones. 

incase you have long ones that go across multiple gridfinity squares, i've added blanks as well