Double Spool Clip - Clips 2 spools together

I have several empty spools stacked with my unopened filament and they kept getting bumped and falling over. I created this clip which uses less than a gram to print that will hold them together while stacked for stability. I've seen plenty of fancy spool organizers, but not something small and simple to just hold them together in a vertical stack. 3 of these clips spaced apart on 2 spools will hold them very securely. Keep on stacking spools as high as you'd like. If you find the limit where the stack falls, post how many it took in the comments.