To convert your Porch Potty for indoor use, we offer an Indoor Catch Basin to make the transition. Or get an extra Catch Basin to fill with water while the other collects the water under the drain. Although the Porch Potty was designed for outdoor use, we've made it easy to bring it indoors in certain circumstances (cold winter months, no balcony after moving, etc.). The Indoor Catch Basin is easy to handle and can hold up 7.57 litres (2.4 Imperial Gallons). Just place it under the Porch Potty, then remove and empty it periodically. This is much easier to handle than a large flimsy drain pan like other competitor dog pottys have. We've tried them all. It wasn't pretty. Our Indoor Catch Basin is an easy way to make your Porch Potty into a indoor dog potty without the mess. The Indoor Catch Basin will work with either Porch Potty Standard or Porch Potty Premium. However, we don't recommend using the automated sprinkler system indoors for obvious reasons. Garden hoses and new hard wood floors don't mix. Size: 46cmx46cmx10cm