one hour sand clock hourglass

Place of Origin:Guangdong, China

Brand Name:Skyringe

Model Number:AM-0153B

... using sand. It is typically made of glass and consists of two connected bulbs with sand flowing through a narrow opening between them. The sand is calibrated to flow at a fixed rate so that it takes precisely 24 hours to pass from one bulb to the other.

Brand Name:Youngth

Model Number:CDC007

Place of Origin:China

... balls and a narrow connecting pipe. Time is measured by the time it takes for a glass ball filled with sand to flow from the top through a narrow pipe to the bottom glass ball. Once all the sand has flowed to the bottom glass ball, the hourglass can be

Brand Name:Zhengzhou Kongsin dental

Model Number:OEM

Place of Origin:Guangdong, China (Mainland)

...Clocks Hourglasses Sand Timer for Teeth Brushing Features 1. Applied to brushing teeth timer with 3 min hourglass, for dental clinic gift. 2. Materials: sand + glass + Plastic Application decoration or gift Type Hourglass Material plastic+glass+sand Color 1/2/3 min Sand...