I think this can safely be called an overly complicated hammer. Squeezing the handle lightly holds a nail in the jaws under the sliding part, which you then hit with a hammer to set the nail. Or squeeze the handles more firmly and the sliding part is locked in place, allowing you to use it as a hammer in the normal way. It can also pull nails and drive screws using hex drive bits.
Location: Box 40
Have you used this tool? Think my description is all wrong? Have a better example? Comment now with any thoughts you have about this tool!