Picked up a new Single Six with the black grips this morning. Took it to the woods and shot it. But when I got home and started looking in the box I found a couple of keys that looked like they went with an internal lock. That's what they are! Locks the hammer down. When did that happen? An internal lock for a single action? I must have slept through that one. But at least you have to take off a grip to use it so there's nothing to distract from the gun's appearance.