http://nguipxnkrp3qrzrlduhsatpcpwehnblzmlkc5ifiumxq4z5jlh4lwvid.onion/os_archive/os_OPSEC_357.html
Make sure you do volume encryption or full disk encryption if you have sensitive data on the airgap. I consider personal financial information ( like taxes, income, planning, purchases, etc) to be in this category that requires an airgap.