Canon EF 24-105mm f/4L IS II USM EF24-105mm f/4L IS II USM Instructions - Page 7

1. Mounting and Detaching the Lens See your camera's instructions for details on mounting and detaching the lens. The lens mount has a rubber ring for enhanced dust- and water-resistance. The rubber ring may cause slight abrasions around the camera's lens mount, but this will not cause any problems. If the rubber ring becomes worn, it is replaceable by a Canon Service Center at a cost. ●●After detaching the lens, place the lens with the rear end up to prevent the lens surface and contacts from getting scratched. ●● If the contacts get soiled, scratched, or have fingerprints on them, corrosion or faulty connections can result. The camera and lens may not operate properly. ●● If the contacts get soiled or have fingerprints on them, clean them with a soft cloth. ●● Attach the lens cap and dust cap when disconnecting the lens. When attaching the dust cap, align the lens mount index with the  index of the dust cap and rotate in a clockwise direction as shown in the illustration. Follow the reverse procedure to detach it. ENG-6