I bought this ups because of the outside the box message "15 minutes backup". But the UPS only with my iMac 2007 can't handle more than 3 minutes when the AC power is out. Fortunately the iMac shut down in a very few seconds and the UPS still OK for me, but BELKIN lies when offers up to 15 minutes of backup time, its a fake. The software that came in the box didn't work neither my iMac nor my PC and i had to download the software in the belkin's web site.