This rubber knife is good for teaching and learning knife disarming techniques, I used these a number of times in my first year of shotokan karate. There is little chance of harming anyone with these. They are not overly flexible yet not too sturdy. They do break quite easily - the 'blade' breaks away from the handle after extensive use.

This weapon is good. It's lighter than I expected but of good quality. I would recommend it to anyone who want to focus mainly on technique. This is also good for light sparring but does leave marks on surrounding surfaces.