Does the blade lock in place?

No. Reviewers report that the blade does not lock, and one warns to be careful because it doesn't lock.

Can I use the bottle opener with the blade closed?

No. According to reviewers, the blade must be open to use the bottle opener, and one reviewer notes that a cut to the hand is possible if your fingers slip.

How sharp is the knife?

A reviewer describes it as super sharp and used it to cut fruit, carve a stick, and cut thick rope while camping.

How big and heavy is this knife?

The listing states it measures just 3.3 inches and weighs only 0.7 ounces, with a blade length of 1.4 inches.

What material is the knife made of?

The listing says it is made from high-quality stainless steel, which is described as strong, reliable, and corrosion-resistant, with a stainless steel handle.