ToughBuilt knife scraper. Press the button with your thumb and you have a scraper. Press it again and it's a knife again. Convenient and saves space in your toolbox. In scraper mode you can easily remove old paint, caulk, stickers. Great for working with windows, mirrors, tiles. In knife mode - cut carpets, cardboard, plastic, rope.  The blades in it are universal. The set comes with as many as five pieces, and they fit almost all other knives. Changing them is easy, press a button and it's done. Its handle is rubberized, non-slip. Sits firmly in the hand, even if you sweat. There is a special protrusion to prevent your fingers from slipping on the blade. There are a couple of other nice little things in it: a can opener for paint cans and a hole for a lanyard.