From Ergon web site:
New for 2009, the GA1 is a specific all mountain grip. Using the knowledge gained in the development of the GE1, the GA1 features a sculpted shape, and various textures to offer many of the advantages of our platform grips, in situations where absolute freedom of movement is called for. Securely bolted [...]

From Ergon web site:
The grip is designed for quick hand position changes in challenging riding and racing conditions. Made from a lightweight rubber compound and combined with a highly secure lightweight clamp, the GX series is the most comfortable grip on the World Cup race circuit.
Very often comfort and performance are opposites and whenever we [...]