I currently own a GoPro Hero 3+ and purchased the GoPro Underwater Waterproof Hero 3/4 Dive Housing Case so I can take it SCUBA diving. I'd like to get the GoPro BacPac Display Viewer Monitor Screen so I can better see what I'm filming. My question is what rear door case do I need to get? I hear the standard GoPro 3+ case waterproof back door is different. thanks.