Grate Litter Mats from Fresh Kitty, a Royal Pet brand, are dual-layered to catch more litter and prevent tracking. The top sifting layer allows for excess litter to fall through and trap in between. Made from BPA-free, high-grade waterproof material that repels liquid waste. Available in large (28 in. by 24 in.) and in medium (24 in. x 16 in.), the product is Prop65 compliance.