Mtech Spring Assisted Knife 3.75in 3CR13 Stainless Steel Reversed Tanto Blue/Steel Blade Stainless Steel Handle Rainbow. The A1107 Assisted Opening knife offers a spring assist mechanism that enables a smooth and quick opening of the blade. A spring loaded plunger on the back of the knife releases the spring to open the blade. Once the blade is open the user has the option of either using the thumb hole or pushing the spring release button to open the knife. Once the knife is open the thumb hole allows easy opening and closing of the knife. This knife is a spring assisted knife so the user uses a spring to open the knife and then pushes the button to close the blade. Specifications for Mtech MT-A1107 3.75in Spring Assisted Knife: Manufacturer: Mtech Blade Length: 3.75 in Blade Material: 3Cr13 Serrated: Plain Overall Length: 8.25 in Handle Material: Stainless Steel Handle Length: 4.5 in Handle Color: Stainless Steel Handle Finish: Tinite Blade Finish: Rainbow Blade Shape: Reverse Tanto Opening Method: Spring Assisted Additional Features: Clip Color: Rainbow Package Contents: Mtech MT-A1107 3.75in Spring Assisted Knife Mtech MT-A1107RB: MT-A1107RB Spring Assisted Knife 3.75in 3CR13 Stainless Steel Reversed Tanto Blue/Steel Blade Stainless Steel Handle Rainbow