How long does the white noise last?
The white noise lasts for about 20 seconds after you turn over the glass. After that, a layer of nanospheres covers the glass and softens the noise.
Is it fragile?
The glass is made from thick borosilicate glass (like original pyrex). It is still glass so care should be taken with it on hard surfaces.
How much does shipping cost?
In the USA, shipping is free. To other countries, the price varies depending on where you live. Keep in mind it's very heavy (1.2kg) and fragile, so shipping costs can be expensive to some countries.
What is the magnetic stopper for?
The free magnetic stopper will stop the flow of the nanospheres in case you get interrupted during your sprint. It's also a cool magic trick to stop the iron nanospheres with the stopper :)