C 4884 Skylark Completely waterproof case, has a 3-point mounting back which allows it to be securely located to any location, once mounted the clock case twists on creating a tight water-resistant seal as well as permanent mounting. A silent sweep seconds hand (no ticking) gracefully sweeps around the dial with bold easy to read numbers. The sky-blue case has a passing white cumulous cloud affect to give it a casual look. The gasketed glass protective lens keeps moisture off the dial. This clock is great choice for Recreational vehicles, boats and anywhere a high humidity or water-resistant timepiece can be used. Uses 1 AA battery (not included) dimensions 10.25" Diameter x 1.75" Dia.