The CAMP Nano 22 used to be the lightest quickdraw made until Edelrid introduced the Nineteen G Set, which includes two of its 19-gram carabiners and a lightweight sling for a total weight of just 47 grams. The small size is best suited for alpine or traditional climbing but also makes a great biner for clipping small hangers or links on anchors. This biner is also available in a six pack and the CAMP Nano 22 carabiner is also sold individually.
The CAMP Nano 22 Quickdraw is not ideal for making clips on sport routes. When compared to the Metolius FS Mini, it is a little less expensive and a little easier to handle. For most applications, we would rather use a draw with a bigger biner that is a little heavier, like the Wild Country Astro Quickdraw, the Black Diamond Oz Quickdraw, or the CAMP Photon Wire Express KS Dyneema. That said, if you are obsessed on having the lightest gear, nothing beats the CAMP Nano 22.