Specifications:

• Shimano Ultegra Cassette 6500
• CS-6500
• 9 speed
• Steel cogs
• 12-13-14-15-17-19-21-24-27t
• Shimano HG Freehub 
• Approx Weight (w/ lockring): 229 g
• NOS, new Shimano cassette in original box. May have some minor evidence of shelf wear from storage, though there appears to be none of note.