Sap

Saps, (also known as a slappers, slap jacks, or beavertail saps), were a type of light, blount force martial melee weapon.

Description
Saps were a lead rod or disk hammered somewhat flat and wrapped in leather, then fitted to a spring handle. The handle could either be an actual spring or a flexible strip of steel. Lead shot (small pellets) was ocassionally used in place of a solid piece of lead.

Weaponology
Saps were designed to deliver blount force blows, dealing out damage for roughing someone up or knocking them unconscious. Knowing where to strike and getting in close enough to use a sap required some skill and thus they were considered a martial weapon. It was possible to kill someone using a sap by striking them in vulnerable areas like the head or chest.