The Totaline P110-1045 water panel should be replaced 1-2 times per humidification season depending on usage and water quality. 100% Recyclable Polystyrene Material - high-quality outdoor cat house can withstand all weather conditions, will not break or rot, and is more durable than a wooden cat house. It can protect stray kittens from the wind and rain, giving them a safe, and comfortable shelter. Safe Shelter for Stray Cats - Our outdoor cat house for winter insulated waterproof is designed with a sloping roof to prevent water and snow from accumulating. The elevated legs prevent water or snow from accumulating and seeping into the cat house. Low Maintenance - The insulated cat house is designed with an open roof and removable bottom for easy daily cleaning. This insulated cat house does not require any special maintenance, usually just wipe with soapy water to clean the surface. Escape Vent - outdoor cat house for winter insulated waterproof has an entrance and window design for cats to enter and exit freely. The entrance and escape windows have removable PVC curtains to keep out the cold wind, rain, and snow. Easy Assembly - outdoor cat shelter simplifies the installation process by using pre-assembled nuts. Screw the screws into the pre-drilled holes, making it easy for cat lovers with no assembly skills.