I made this pack especially for long multipitch route of rock and ice climbing so I avoided external gadget and I used cordura 1000. The zipper and the webbing are from an old school pack. Volume is approx. 20 liters. This would be a great project for a begginer gear maker.
The desing is from my own so I made the pattern to build this kind of bag. I sell the pattern 5$ (US) wich is pretty cheap according to the time you'll economize. If you want yours, just send me a mail at: email@example.com