A knife assembly includes a handle having a first and second handle portion each extending in spaced relationship with one another between a first and second knife end to define a working gap. A knife blade is pivotably secured to the second knife end and pivotable between a closed and engaged position. A switch button is interconnected to the handle for releasing the knife blade from the closed or engaged positions. A spacer is disposed within the working gap and extends between the first and second handle portions. A vial of tritium is housed within the switch button for allowing tritium produced by the tritium vial to be viewable by a user of the knife assembly.