The Spinfire Tennis Clamp V100 is a more advanced clamp for those who care about quality clamps. The structure of this clamp is more complex than the V20, with a gear inside giving the user a smoother feel when adjusting the for different gauge strings. Most importantly though, the adjustment wheel is recessed inside the clamp which allows the two clamps to get closer together while clamping strings. It's a very clever design only seen on more expensive machines.