I love the P60 concept and have several hosts and lots of modules that need more than a tiny ziplock bag for storage. A rigid plastic Fujifilm film container is about the right size, and it works best with 3/8" closed cell foam on the bottom. Fujifilm containers are clear and have a cap that snaps inside. I store the P60 module head down, and the spring fits nicely into the center recess on the cap. A label on the outside records the brand, emitter, voltage range (i.e., 4.2V max or 8.4V max), and other relevant info. You may be able to get these containers for free from your local photo shop, but I bought a bunch on Ebay for about 15 cents each.