This 4 tier storage bin was exactly what I was looking for to use in my shop with some lightweight items. The tabs between layers are not quite as reinforced as they probably should be, and as such are prone to snapping (which leads to the inability to connect layers). However, the customer service of the company more than makes up for it! When reached out about the broken piece, they replaced it without any hassle!
Its the pefect amount of height for the size of the bins, and the smaller size makes it great for being able to store among other things on shelves when not needed. The two sorting trays are durable and each have 6 slots, the side slots are just slightly smaller than the center slots. The 2 layers without sorters make it easy to store any extra working tools or other items that are bigger than the sorting slots, but related to whatever is being kept inside!