Polaris' cutting boards are made from Rubberwood, a very durable material. Each cutting board is custom made to fit your sink and will work best with a 3/8" positive reveal or flush cut installation. They will not, however, fit a sink with a negative reveal installation. Custom-fit cutting boards can be a great addition to any sink. Those who love to cook will appreciate the usefulness of having a cutting board over the sink, not taking up countertop room. And, those who occasionally use it are sure to enjoy its lightweight body and easy-to-grab cut-out for effortless handling.