A cookie-cutter was shaped like an aspirin tablet except that the top and 
bottom were domed more to withstand ambient pressure; for like most other 
nanotechnological devices a cookie-cutter was filled with vacuum. Inside were 
two centrifuges, rotating on the same axis but in opposite directions, 
preventing the unit from acting like a gyroscope. The device could be triggered 
in various ways; the most primitive were simple seven-minute time bombs.