Wise BM1143-1B-990 Premier Series 27" Pontoon Seat Base designed as a precise fit with Wise BM1143-986, BM1143-988 and BM1143-989 Premier Series 36" Pontoon Bench Seat Cushion. (sold seperately) Constructed of high density rotational molded plastic that is mar, scuff and mildew resistant. Storage compartment with built in water drain holes. 5 Year Warranty. Base Dimensions - Length: 27", Depth: 19", Height: 11"