z Sterile 20cm Vintage all metal Gravity knife Silver colored OTF

No markings on the blade of this all metal silver colored Gravity knife. It measures 19.5cm (7.75 inches) open with non magnetic handles/frame. Most likely non magnetic Stainless Steel. The blade looks full with original finish. The knife works great. Blade drops out if you tip it down and press the release button and drops back in if you tip it up and press the button. not sure on the age, or origin, but it's a very cool all metal gravity knife.