One that is deployed!
Brother-in-law's small business took a power hit which half baked his SOHO firewall and clobbered connectivity for workstations and more importantly, the credit card processing machine.
He got a replacement firewall up and running. I suggested placing the new device, internet modem, credit card machine and PC used for billing on UPSs. He said oh, I have a couple of nice ones sitting in the closet that a vendor rep gave me as part of an equipment deal (a few years ago).