Emergency screens
Tap what's happening (bleeding, fire, flood, lost, no power…) and Cairn shows what to do first, then what next.
1,600+how-to sections
660+printable cards
100+field manuals and classic books, converted to easy pages
25topics
50states mapped
What's inside
From the first minutes to the long haul
Plug in the drive and open index.html in a browser. Everything below is on the drive.
The long haul
Safe water, food and preserving, power, medicine, home repair, homestead and old-time trades (blacksmithing, pottery, casting, wells, draft animals) for days, weeks or longer.
The library
Wikipedia, medical encyclopedias, field manuals, textbooks, classic books, and an offline street map of all 50 states.
Also inside
- Precious-metals calculator: value gold and silver offline
- 9 two-player family games
- Puzzles and coloring pages
- Legal templates
- The US founding documents
- Scripture
- A Spanish shelf
25 topics
Everything a household might need to look up
- Emergency and first aid
- Medic's handbook
- Family health
- Water, fire, shelter
- Food and preserving
- Recipes
- Herbs
- Homestead and animals
- Hunting and fishing
- Power
- Home systems
- Vehicles
- Repair and old trades
- Comms and navigation
- Plan and prepare
- People and trade
- Legal and money
- Your rights
- Faith and scripture
- Learning
- Technology
- Español
- Family and fun
- Using Cairn
How it works
Three steps. That's all.
Open
Double-click index.html on the drive. It opens in your browser.
Start
Run START to search inside every library on the drive.
Share
Run SHARE. Phones on the same Wi-Fi scan a QR code.
About phones: Cairn runs on a Windows, Mac or Linux computer. Phones read it over Wi-Fi from a laptop that's sharing it (scan a QR code), or from the Base Station.
Compare
Pick the one that fits your drive
| Feature | Pocket 128 | Pocket 256 | Full library |
|---|---|---|---|
| Fits on | 128 GB stick | 256 GB stick | 1 TB drive |
| Guides, emergency screens, printable cards, 100+ manuals | ✓ | ✓ | ✓ |
| Street map, all 50 states | ✓ | ✓ | ✓ |
| Medical libraries | ✓ | ✓ | ✓ |
| Precious metals calculator, family games | ✓ | ✓ | ✓ |
| Wikipedia | Top 1 million articles, text | Every article, text | Every article, with pictures |
| Dictionary (Wiktionary) | — | ✓ | ✓ |
| Survivor Library (1800s how-to books) | — | 4,500-book selection | 4,500-book selection |
| Español | Core shelf | Core shelf | Full Spanish shelf |
| Kids | Kids' encyclopedia, games | Kids' encyclopedia, games | Adds picture-book libraries |
| Download | $19 | $29 | $39 |
| Ready to use | — | $99 Pocket | $199 Home · $499 Base Station |
Swipe the table sideways to see every edition.
Buy Cairn
Choose your Cairn
Download it to your own drive, or get one built, loaded and tested by RoamRock.
Download
Use your own drive. One-time price.
Download
Pocket 128
Fits on a 128 GB thumb drive
$19
One-time purchase
- Guides, emergency screens, printable cards, 100+ manuals
- Street map, all 50 states
- Medical libraries
- Wikipedia: top 1 million articles, text
- Español core shelf; kids' encyclopedia and games
Download
Pocket 256
Fits on a 256 GB thumb drive
$29
One-time purchase
- Everything in Pocket 128
- Wikipedia: every article, text
- Dictionary (Wiktionary)
- Survivor Library: 4,500-book selection of 1800s how-to books
Download
Full library
Fits on a 1 TB drive or larger
$39
One-time purchase
- Everything in Pocket 256
- Wikipedia: every article, with pictures
- Survivor Library: the same 4,500-book selection
- Full Spanish shelf
- Adds picture-book libraries for kids
The drive you need
- Pocket 128: a 128 GB USB drive (about 110 GB of files)
- Pocket 256: a 256 GB USB drive (about 225 GB)
- Full library: a 1 TB drive or larger (about 550 GB)
Free Cairn Setup does the rest
After you pay you get a download key. The free Cairn Setup app downloads everything onto your drive and checks every file. Then open index.html on the drive.
Windows first
Cairn Setup runs on Windows. On Mac or Linux a setup script does the same job; step-by-step instructions are on your order page.
Ready to use
Built, loaded and tested by RoamRock. Plug it in and open it.
Drive
Cairn Pocket
256 GB keychain flash drive
$99
Pocket 256 edition, ready to use
- Everything in the Pocket 256 download
- Loaded and tested before it ships
- On your keychain, ready when you need it
Drive
Cairn Home
1 TB portable SSD, everything
$199
Full library, ready to use
- The whole Cairn library on one portable SSD
- One laptop shares it to every phone in the house
- Loaded and tested before it ships
Base Station
Cairn Base Station
Always-on box with its own Wi-Fi and battery backup
$499
For a homestead, church or group
- No computer needed
- Phones and laptops nearby connect to its Wi-Fi
- Battery backup built in
Updates · $39 a year
Coming soon
An add-on for your Cairn. Not on sale yet.
Card or bank payment on Stripe's secure checkout. Your card and bank details never reach us. Questions before you buy? Contact us.
Questions
Good to know
What drive should I buy for a download?
Any USB drive from a brand you trust, at least as big as your edition: 128 GB for Pocket 128, 256 GB for Pocket 256, and 1 TB or larger for the Full library (at that size a portable SSD is usually much faster than a thumb drive).
Format it as exFAT so it works on Windows, Mac and Linux. On Windows: right-click the drive in File Explorer, choose Format, pick exFAT. On a Mac: Disk Utility, Erase, pick ExFAT. Formatting erases the drive.
How long does the download take?
It's big: about 110 GB for Pocket 128, 225 GB for Pocket 256 and 550 GB for the Full library. The time depends on your internet speed. Roughly:
| Edition | At 100 Mbit/s | At 25 Mbit/s |
|---|---|---|
| Pocket 128 (~110 GB) | about 2½ hours | about 10 hours |
| Pocket 256 (~225 GB) | about 5 hours | about 20 hours |
| Full library (~550 GB) | about 12 hours | about 2 days |
Leave the computer on and plugged in while Cairn Setup works, and check whether your internet plan has a data cap. If you'd rather skip the wait, a ready-to-use drive arrives loaded.
Does it really work with no internet?
Yes. Once Cairn is on the drive it needs no internet, nothing to install and no account: plug in the drive and open index.html in a browser. Only the first download (for the download editions) needs the internet.
Do I need an account?
No. You pay on Stripe's checkout with your email for the receipt. Your order page and download key are all you need, and you can find your order again any time with its number and your email.
Can I use it on my phone?
Cairn runs on a Windows, Mac or Linux computer. Phones read it over Wi-Fi from a laptop that's sharing it (run SHARE, then scan the QR code), or from the Base Station.
I lost my download key.
It's on your Stripe receipt, and on your order page: use Find my order with your order number and the email you paid with.
Can I get a refund?
Contact us (hello@roamrock.com) with your order number and we'll sort it out with you.
Is this medical advice?
No. Guides are general information, not medical or professional advice. In an emergency, call 911 first if phones work.
Have it before you need it.
Emergency guides, maps and a whole reference library on one drive. Downloads from $19, ready-to-use drives from $99.
Guides are general information, not medical or professional advice.