If you took a push knife and stripped it down to its barest essentials, it might look something like the BLADETRICKS Stop Switch. The spike like “blade” flares to a rounded handle with G10 scales that rests against the palm the same way the handle on a push dagger would. This compact, minimalist design makes Stop Switch easy to carry and intuitive to use.
The Stop Switch is custom made by BLADETRICKS so the specs vary from knife to knife. The one shown below with yellow G10 handle slabs is ground from 3mm thick 6150 steel with an overall length of 70mm (2.75″). You can view it and other custom knives at BLADETRICKS.net.