This solid brass porthole tide clock features a quartz movement and thick glass incorporating a polished bevel around the outer edge and the clock is 8½”diameter with a 5¾”diameter face. The two dogs on the porthole unscrew, allowing you to open the clock for cleaning or time adjustment. Please note that due to the Pacific Oceans irregular tide patterns, tide clocks located on the Pacific coast will need to be reset more often. This nautical clock makes the perfect addition to your nautical home decor. It could help turn that special area in your nautical home or office into your own beach house, coastal themed area. They also make a great nautical gifts, a beautiful piece of coastal decor, a nice piece of nautical wall art as well as being a great addition to your nautical decoration.