Act as a cushion and spacer between the handle and the stone.

It typically helps with:

• Reducing vibration and shock when the stone is delivered or hits another stone.
• Preventing the handle from loosening by maintaining a little tension between the handle hardware and the stone.
• Protecting the stone and handle from direct metal-to-stone contact.
• Compensating for small variations in the handle/stone mounting surfaces.
• Keeping the handle securely seated without requiring excessive tightening.