@mattthemuppet2
I have no idea what's in them but I see hundreds of $$$ worth of tote pans there. They can be a great aid in organizing.
In case you don't have much experience with them, let me give you a few tips.
The totes stack nicely, BUT the bottoms can fail if heavily loaded, over time, and not sitting on a solid support. Using a cover on each tote has provided sufficient support for the bottom above, in my experience. I see that the price of covers is high now, IMHO, at McMaster, but you can shop for a better deal at other suppliers or maybe the manufacturer will sell direct. Try Zoro with a 20% off coupon and free shipping over $75.
There are (were?) also at least 3 styles of covers. One style is just a flat sheet that sits in the recess on the top flange of the tote. Another type is made of the same material as the box, fits over the the top flange of the box and includes a 1" (or so) deep skirt around the perimeter. The 3rd type is made of a relatively clear plastic and seems like a vacuformed part that snaps on the top flange. The flat ones are really dust covers and may not provide much support for a heavy load. The second type are probably the best support and most expensive. I generally use the third type because they were less expensive, I can see what's in the tote and I keep the weight down on stacked totes.
Another option I've considered (not done yet) is to cut a sheet if 1/4" plywood to fit into the bottom of the tote. However, if substantially overloaded (stacking a few heavy totes), the side walls of the lower one might tend to open up. Using types 2 or 3 covers restrains the top flange of the tote to prevent that distortion.
Of course, you can use them safely, unstacked, resting on a solid surface.
How did that become so long winded? I hope it helps.
McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
www.mcmaster.com
Edit: McMaster used to sell both the type 2 and 3 covers that I described. I suspect the only type currently listed is the type 2. My guess is based on the price. If so, it's probably the strongest option for stacking on, but it's opaque. Only a guess.
called a Hunter Sure Fit 2200-3....for $8 and last but not least....drum roll please......a Interapid test indicator .0001 resolution Model 312-B3 in the box with all the trimmings, like new....for $10!!! Happy Dance!!! 
