Blade Boots
From Traykon Campaign Setting
Cost 25 gp Weight 2 lbs.
Damage 1d3 (small), 1d4 (medium) Critical x2 Type piercing
Category light Proficiency simple
Blade boots come with a spring-mounted knife that pops out when triggered with the right combination of toe presses.
You can use a blade boot as an off-hand weapon. Releasing the knife is a swift action; rearming it is a full-round action. When the blade is extended, you treat normal terrain as difficult and difficult terrain as impassable.