Simple Independent "Stop" or "Hold" Button

Hello, everyone. Given the level of tech discussions this is ridiculously elementary, but has anyone ever heard of a hand held device - wired or wireless - consisting of a simple button that allows the scanner user to hold or pause a scan and then re-start it ? For mobile use especially, having to reach over and pick up the handheld, or push the right button on the mobile unit console, could be a distracting and dangerous affair, to say nothing of fouling up the scan if the wrong button is pushed. Thanks !