The TR-GP is a small tray for the housing which can then take a handle. It comes with the GoPro tripod mount. The handle gives you the ability to add a light to the unit.
The AD-GO is a ball adapter designed to fit directly onto the tripod base and then onto the GoPro housing. The ball can then be used with a variety of Ultralight clamps and adapters to allow the housing to be mounted almost anywhere, i.e. onto the aiming light shoe of an SLR or video housing.
For the ultimate strength the GP-Cage is an aluminum cage that fits over the housing giving you a ball at the back allowing you to attach it with a ULCS clamp to your housing or on an arm. This cage eliminates the use of the plastic tabs below the housing which can easily break off in extreme conditions.
The cage can be attached to jet skis, motorcycle handle bars and bicycle handle bars with other parts.
For more info www.ulcs.com