Designed for use on boats wherespace is at a premium. It works using the same principles as the above standard heaters with no difference in performance or efficiency. May be installed both in vertical or horizontal position. Dimensions (L x D mm) - Kg: 15L: 505 x 295 - 8Kg 20L: 630 x 295 - 9Kg 25L: 750 x 295 - 11Kg