There is a tiny batch of Ultralight Pinky Karambits available at Bladetricks.net:
Designed and handcrafted one by one by knife maker A.N. Nash, these little karambits are a good option for those looking for a last ditch / backup neck knife.
This last batch is made of 4340 alloy, a very high strength steel sought after for its toughness and used for parts that will be highly stressed in applications requiring the highest tensile/yield strength (Military aircraft, Heavy Duty crankshafts and any other highly stessed parts). 4340 alloy steel is probably the toughest steel availble and we love to work with it in our workshop in order to make the toughest and most rugged knives and blades available at a rasonable price.
More info?