Amazon.com: Drymate Whelping Box Liner Mat, Washable and Reusable Dog Puppy Pee Pad - Absorbent/Waterproof/Durable - Can Be Cut to Fit (USA Made) (48" x 50") : Pet Supplies
Liner for EZclassic Whelping Box - EZwhelp
Whelping Box Disposable Liners @ BreederBase.com
Tucker Murphy Pet™ Whelping Box Liner Mat, Washable And Reusable Puppy Pad, Can Be Cut To Fit | Wayfair