Stanley 199 "Classic" trapezoidal blade knife
Heavy duty Stanley utility knife ~ semi-fixed blade
The original has been very slightly modified over the years, but there has been no significant change since early in the 1900's. The handle holds half a dozen spare blades (and is a good place to store used blades until they can be safely disposed). The blade quite thick and strong, and is very firmly held in place. A small protective plastic sheath is provided, but is very difficult to fit onto the blade (and this needs great care in view of the proximity of a very sharp blade and point). Two disadvantages are tool required and the time taken for a blade change (as opposed to snap-off knives), and the need to stow the knife away carefully in the toolbox to avoid unintended and accidental cutting.
The knife is supplied by us with three blades stored inside the handle for safety in transit. The illustration shows retail packaging, with a printed blade on the display card.