Rough Ryder Desert Fox Jumbo Trapper RR2305, slipjoint pocket knife

You open the Rough Ryder with two hands. To make this easier, there's a nail nick which gives you a little extra grip using your fingernail. This pocket knife is not equipped with a full lock, only with a slipjoint mechanism. This provides some resistance to prevent the knife from snapping shut during normal use. However, if you press on the spine of the blade, the knife will shut.