EF-USBDVR. The Yale EF-USBDVR CCTV / Alarm Adaptor allows its users to control and monitor owned Easy Fit alarm systems through the CCTV kit DVR's menu and the mobile application. This dongle makes it possible to turn the alarm of the system on or off from a remote location by using the Yale app on either a smart phone or tablet.. To suit the Easy Fit CCTV Kit. Dongle. .