Spare batteries for your Spider Pen.
There will come a time when your new Spider Pen will need either replacement batteries, or a new thread reel. This is normal. Your batteries will eventually need to be replaced, and after extended use, the thread reel that is built into the pen will eventually need to have a new supply of thread installed.
Get these replacements now, instead of having to wait for them to be shipped to you. There is nothing worse than needing something and not having it available to use.