Have an extra CR-2032 battery backup on-hand for any of your Vortex illuminated riflescopes. Vortex CR 2032 Battery holder mounts on a Picatinny rail and comes with a tethered cap. It holds one CR2032 battery. It is watertight and provides dustproof storage. The retaining cable secures the battery holder cap and prevents you from losing it. It allows for quick access and ease of mounting using a coin, a flat-head screwdriver or any tool with a flat shape.