The Chrome Endurance 125 Time and Tide Clock features a combination quartz time and tide clock movement. The tide sector averages the Atlantic lunar tide cycle.The easy-to-read dial, maintenance-free chrome finish and weatherproof construction make this generous size tide clock one of our most popular. The patented Slide-n-Lock Mounting System eliminates the need for visible mounting screws and is easily removed for adjustments and battery replacement. Easy-to-read generous size dial Combination quartz time & tide movement Tide sector calibrated for Atlantic lunar tide cycle Note: Tide calibration for other tidal bodies of water will need to be reset frequently, e.g., Pacific Ocean & Gulf of Mexico Red tide indicator points to “high tide,” "falling," low tide,” & "rising" Black hands indicate the current time Maintenance-free, ultra-hard chrome finish guaranteed to never tarnish Patented Slide-n-lock™ Mounting System Beveled glass crystal O-ring seated behind glass for splash proof construction AA battery included Lifetime warranty United States Patent: 7,293,456BI / 8,381,585 / 8,925,381 Dimensions: Dial: 4 7⁄8 ” (124 mm) Overall Diameter: 6” (152 mm) Depth: 1 5⁄8” (41 mm) Weight: 1.3 lbs (589 g) UPC Code: 721002004109