This blade separates to allow you to pass the blade through a hole in your glass.
This permits you to make inside cuts without a lead-in.
When replacing the blade, be careful to keep the two gold pulleys that you moved a little bit away from the blade. You do not want to have the pulleys tight against the blade. Their purpose is to limit side-to-side movement of the blade, so a bit of looseness is beneficial.
For Zephyr Saw.