Zephyr Separating Blade 120 Grit.

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.

The attached video shows how to install a new blade.