these are from Home Depot; originally they were "HDX" branded, now "Anvil," and currently $18 for a pair. i use the same ones for organizing electronic components, and they can snap together into a stack of two or more should you desire. they've held up great for years since i operate and they go with me at least once a week on my rounds. i suppose at this point i should just toss the extra dividers since it's unlikely i'm going to change this layout.
i like these because they are lightweight, a reasonable size, and not much wasted space.
i work in event production and always have gaff tape and a Sharpie around so that's what i used to label.
and yes, i'm prepared to get flamed for using standard black rubber.
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