From the manufacturer's official website:

Computer designed Hyperglide (HG) sprockets incorporate specifically positioned shift ramps and tooth profiles for improved chain control during shifting. Fast and responsive indexed shifting is the result.

Features:

• Cassette Sprockets Combinations
  • 11,12,13,14,15,16,17,19,21,23
  • 12,13,14,15,16,17,18,19,21,23
  • 12,13,14,15,16,17,19,21,23,25
  • 12,13,14,15,16,17,19,21,24,27
• Junior Gearing
  • 13,14,15,16,17,18,19,21,23,25
  • 14,15,16,17,18,19,20,21,23,25
  • 15,16,17,18,19,20,21,22,23,25
  • 16,17,18,19,20,21,22,23,25,27

Specifications:

• Speed 10-speed
• Finish nickel plated
• Average Weight 235g (12-13T)

For more information, please visit this product's webpage.