From Panasonic, the NAiS CH631 is the best functioning and most reliable seat on the market today. Hygiene For Health® has sold this model since 1995, and little has changed with a design that is proven to be the best. Over 85% of these are still in use today – 18 years later. Optional Kohler mounting brackets for installation on the Rialto and San Rafael one-piece models is available at no charge when ordering. If you want the best seat we can offer, this is it.