Open Fist - This weapon is an Open Fist. A model can use a weapon with an Open Fist to make some power attacks:

• The following model types (warbeasts, warjacks, horrors, and monstrosities) can use it to make a throw power attack.
• Gargantuans and colossals can use it to make either a throw or a power strike power attack.
• Warjacks need to have at least one non-crippled open fist if they want to perform one of the aforementioned power attacks. (The other model types don't suffer crippled systems).