Measure the packed size before buying
Use outside dimensions to check a drawer, pouch or travel organizer.
Ask which object was measured
Start by deciding what you will store together. That could be a sleeve alone, a sleeve inside a supplied case, or a sleeve in a separate organizer. Look for the outside measurements of that complete setup. If the numbers appear next to shipping weight, check whether they describe the carton.
For example, a four-inch insertable length describes the inside of a sleeve. It gives you too little information to decide whether the closed case fits in a five-inch drawer. Ask for outside length, width and height with the lid shut and any handle or hinge in place.
Measure the opening as well as the space
A deep drawer can still have a shallow opening. Measure the narrowest point and leave enough space to lift the case out. If you already have a pouch, make a paper rectangle to the listed footprint and see whether it passes through the zipper opening.
Check the exact listing before buying
Compare the title, selected option, included-parts list and product photos. The case-style Pocket Pals listings explicitly mention a compact case. The standalone listing uses the same family name but does not confirm a case. Ask the seller if the accessory is essential to your choice.