The Ontario FF6 Trainer is the training knife for the Freedom Fighter 6. It is a rubber knife that can be used to practise disarmament techniques. These techniques are taught in various martial arts. During training, it is great to do this with a dummy knife, as it is a good bit less dangerous than using a real knife.
Incidentally, this model is of course very similar to other USMC-like fixed knives such as the KA-BAR 1217. This training knife can therefore serve as a good substitute for those kinds of real knives.