It's a jar or lid opener.

Amen. Love to watch RedGreen. Even in the States he has them beat.

Agree with the tripwire gun. I saw one similar in a museum.

Aww come on... Let you dogs come out to play for just a little while...

"...The gun is a single-shot flintlock, made by Philadelphia gunsmith Henry Derringer. It’s tiny - just six inches total in length with a 2 1/2" barrel - but it’s powerful, firing a .44-calibur bullet."

The gun shown is not a flintlock, rather it is a caplock.