Answer: you can install the lens cap, the same diameter can be 

hi,please choose 67mm lens cap. 

The V50x comes with a skeleton case with a slotted rear door replacement, but there is no opening to allow plugging in an external mic. As a note, the sound recording, even while in the completely waterproof case, is better than I had expected. If you're not worried about moisture, there is a threaded tripod mount on the bottom of the camera and an adapter that will allow you mount the camera without using the case. 

This will work on any 82mm lens. 

Same caliber can be installed the lens cap