Ultimate Survival Klipp Lighter measures 3" x 1.8" overall and is a great idea as you can clip it just about anywhere. It is a high performance butane lighter with an intergrated carabiner design so it is always ready when you need it.
Zinc die-cast locking carabiner for attachment to packs, gear, or keychains
Windproof turbo flame with piezo-electric ignition which lights up to 30,000 times and works when wet
Fuel Capacity: Quadruple-refined butane 0.04 oz. (1.2g)