For 2.5" Port Opening High Quality Glass Optics Wide Angle Ports contain several lens elements to encompass a larger underwater view. It is by far the most commonly used port as it affords a very broad field of view and large depth of field. Large animals or big reef scenes can be captured with sharp focus on both near and far subjects. They usually have little or no zoom capability. The high-precision glass WP-series is part of the Gates Precision Port family. 
Wide Angle ports are a part of any underwater imaging kit. They are highly recommended for those new to underwater imaging because they make it easy to ‘point and shoot’ with straightforward success.