The case of the Sirius v2 comes with an extra blade but not really a great way to store it. This keeps the live blade safe and also secure just in case. I have both the live and tuning fork trainer blades so it fits both. It fits snugly in both of the knife-holding straps. It also has a spacer in case you'd like to make taking a blade out easier.
The author marked this model as their own original creation.