The rise of the ramp is the vertical dimension and the horizontal projection or run of the ramp is the horizontal dimension. If the slope of a ramp is between 1:12 and 1:16, the maximum rise shall be 30 inches (760 mm) and the maximum horizontal run shall be 30 feet (9 m).
GoPro, Inc. (formerly Woodman Labs, Inc), is an American manufacturer of action cameras, often used in extreme-action videography.
The GoPro Hero HD is squarely based off the old model. It has the same mounting system, case, physical shape and user interface. It is so similar, I suggest you read the original short review I did and then come back here for the low down on what makes this one better. Here's the link.