I didn't need to cut out any sections of my sump when installing a Reefmat filter roller system, so I didn't need to use the 'sump modification kit' during install. This kit contains super-flexible and thin blades for the purpose of cutting the silicon out of a sump to allow the Reefmat to fit.
This video shows what the tools are used for:
New and unopened. Pick up in Rhode Island.
This video shows what the tools are used for:
New and unopened. Pick up in Rhode Island.