Survival Grips are a 1913 rail mounted vertical grip with 6061 aircraft aluminum finger guards for "increased control and weapon retention." They come in black and polished aluminum in both standard and spiked variants and range in price from $49 to $70. The metal guard also detaches from the grip for, well, any occasion you might encounter where it would be good to have metal around the knuckle area.
Find them at www.survivalgrips.com
