This product is an 11T sprocket with 12mm bore for the 219H chain to run on your X1 Pro or X1 Stealth kit.

Compatibility:

• X1 Stealth Gen 3
• X1 Stealth Gen 1
• X1 Pro Gen 4
• X1 Pro Gen 3
• X1 Pro Gen 2

Note:
The X1 Stealth Gen 1 pressfit versions with Freewheel 2.0 have a special 11T to accommodate for the chainline.