This is the Stanley FatMax Utility Knife model 10-481. Up until now I have been using the inexpensive, throw away, plastic knives. The ones I have use 2 buttons; one to lock the blade in position, the other to slide the blade in and out. FatMax has just one button that does both functions. And it has some weight to it. It feels substantial. Spare blades are stored inside. It just seems all around more comfortable to use.