Did you know that there are millions of Mason jars are currently in circulation in North America? Why not find a second use for all those jars! This Cheese Grater Lid for Mason Jars from Starfrit is designed to screw onto a regular Mason jar. Simply screw the collar onto a regular Mason Jar (sold separately) to transform your Mason jar into a Cheese Grater! The grater is even dishwasher safe.