The grey stone in this kit is meant to be used on glass, crystal and ceremic calls. Just place the corner of one of the ends of the stone on the call and work side to side until you reach the desired conditioning. DO NOT press to hard or you might break the call surface.
The green pad in this kit is meant to used on slate calls. Just place the pad on the slate and work side to side until you reach the desired conditioning.
CAUTION: DO NOT use the stone in this kit on a true slate call. You could ruin the slate in the call by cutting deep grooves in the slate with the stone. Use only the green pad on a true slate.
Hook's Custom Calls
825 Reed Wade Road
Batesville, AR 72501