Assisted Opening Knives (spring assisted knives) for sale. en.wikipedia.org/wiki/Assisted-opening_knife
SW SORTB Spring Assisted Opening Knife
Smith & Wesson SWSORTBS Spring Assisted Opening Knife
Smith & Wesson Medium SWAT SW5000 Manual Knife Satin Combo Blade
Smith & Wesson SW4000B Medium SWAT Manual Knife Black Plain Blade