The fillable sand timer has two connected vertical glass bulbs allowing a regulated trickle of material from the top to the bottom. Once the to bulb is empty, it can be inverted to being timing again. Factors affecting the time include the amount of sand, the bulb size, the neck width, and the sand quality. This decorative hourglass timer is also a good gift for home or office decoration It's an empty hourglass, you can DIY the empty hourglass and fill your own hourglass.
