Lightweight hardwood with an upper portion that rests on the brim of the Revel 2021 - 2023 and has a lower portion that fits down into the sink to hold it in place.  These items are made to order and take 2-4 weeks to arrive.
 
Though bamboo is a naturally hard material, ideal for cutting boards, it is suseptable to dehydration.  Bambu Finishing Oil is a great product to use 1-2 times each year to clean and rehydrate the bamboo.