I have no idea what these are, so don't even ask. I will, however, provide the extended description direct from the manufacturer to illuminate you should you be more understanding than I am: "Pillows remove easily when adding new services. Self-contained, intumescent product for use in a wide variety of through-penetration firestops including cable trays, conduit and blank openings. Provides up to 3-hour fire protection. Large self-locking pillow: 3 x 6 x 9 (76.2 mm x 101.6 mm x 241.3 mm). During a fire, 3M™ Fire Barrier Self-Locking Pillows intumesce (expand) and lock themselves into place, surrounding the penetrant(s) to help prevent the spread of smoke, fire and toxic gases. Easy-to-install 3M™ Fire Barrier Pillows are ideal for projects requiring re-enterability of the firestop system. Simply remove and replace pillows as needed. Any combination of small, medium, or large pillows can be used to firestop an opening provided the minimum compression requirements are met (minimum of 33% within the opening)."
So there you go. The box is opened, but none of the pillows inside have been opened or touched, and all still have the interlocking strips. INDIVIDUAL ones retail for $35, with these 20-pack cases going for over $400 elsewhere!
We only have one box available, so grab it before it's gone for good!