Tekna Security Card Knife Double Fixed Blade Knife Double Edge Handle TEK-SC DOUBLE EDGE. Specifications for Tekna Security Card Knife Double Fixed Blade Knife: Manufacturer: Tekna Blade Shape: Double Edge Blade Material: Steel Knife Application: Fixed Blade Handle Color: Black Handle Finish: Satin Closed Length: 3.25 in Package Contents: Tekna Security Card Knife Double Fixed Blade Knife Tekna TEK-SC DOUBLE EDGE: Security Card Knife Double Fixed Blade Knife Double Edge Handle