Most filters for the GoPro only come in one colour: Red. In theory it makes sense, you are attemting to remove the greenish tint in footage and return to bluewater. If you're diving and filming in loads of different conditions, why would one filter be sufficient for them all? The Flip 4 filters have undergone hundreds of hours of underwater testing to ensure that each filter provides the best performance possible, and that the range of filters covers as many diving conditions as possible.
The Flip 4 Pro Package and 3 Filter Kit both include the 2 filter body. This allows for a filter to be mounted on the top and side of the GoPro lens, making it easy to switch between filters on a dive as the conditions call for.
Made out of incredibly sturdy aeronautic grade aluminium the Flip 4 is much more secure than clip on filters, but isn't permanent like others and can be removed from the housing easily.