This is a 5-pound weight. It weighs 5 pounds.
The abbreviation for 'pound' is "lb". Nobody knows why. It is old English.
1 kilogram = 2.2 lbs.
This blog is mainly to explain a different English language expression every day. Sometimes I post other stuff. I also have a YouTube channel which is mostly about computer software: https://www.youtube.com/englishspacedog